Aerodynamics of Gravel Bikes | Hacker News Reader

Aerodynamics of Gravel Bikes

renehersecycles.com

151 pointsvinceroni206 comments

I am an out of shape former racer who has ridden his bike 10 times in the last two years. I have a dad belly and rarely work out at all. I recently did The Rift this summer - a 200km gravel race here in Iceland that people come from all over the world to race. I did it on a carbon cyclocross bike from my racing days with file treads. I felt like the light weight of my bike outweighed just about every gravel fad that's out there right now. I was flying past people on the hills, and while the ride felt very rough on the high speed flats, I was still going fast. If I were in my racing shape of a few years ago I think I would have been in the top 5-10% of racers, largely because nearly everyone was on giant heavy gravel bikes with massive tires loaded for friggin bikepacking from the look of it. My wife has a purpose-built gravel bike, and she commented on just how slow it felt going uphill (she is a former state cyclocross champion).

With the exception of the absolute professionals, most people "Racing" these events are just there to finish them, and the pros? It's basically just a road race. Gravel offers no significant challenge in handling your bike, and any reasonable set-up can win if it's light enough and the rider is fit enough. The Aero arms race certainly matters in time trials, but I remain unconvinced there's enough benefit for the actual racing. I know US Midwest gravel races are effectively flat, but acceleration is greatly improved with a light bike too.

> I know US Midwest gravel races are effectively flat, but acceleration is greatly improved with a light bike too.

While this is a "on the paved road" race... you should check out Horribly Hilly Hundreds in Wisconsin - https://www.horriblyhilly.com

Yeah, rolling hills are tough…. “Rouleur” is a cyclist type for a reason.

Why don't you actually do some math, or experiments, rather than just telling us you have doubts?

This is all really easy stuff to answer. For instance. 75kg rider + bike. Make the bike 1kg lighter. Go up a 8% grade for 1 kilometers at 300 watts Time saved by 1kg weight reduction? 30 seconds out of 40 minutes.

Or suppose we add 300grams to the frame to make it aero, which is typical. If that reduces the CdA by .02 out of .25, you are at about a breakeven point. JUST during the 1km climb. Then you save time on all the flats and non technical downhills.

Acceleration is even less affected by bike mass. People forget that bike mass is a tiny % of total system mass (our fat asses). And mass is only one of 4 major components that affect acceleration. I'm happy to run through some acceleration scenarios if you like.

You are correct on the watt, weight computes but I think the aerodynamic saving is worthless on a gravel race. People are not going that fast on gravel to gain anything from aerodynamical optimisations. You need to keep going at least 40 km/h to have any advancement without up-down movement which is obviously not something that you can achieve on gravel.

Aero also helps at 25 or 30kph.

It is quite easy to check out actually on a road bike. Ride at a steady pace without pushing hard, hands on top, then put your hands in the hoods of the brake lever, elbows at 90° without pushing more, you will gain easily 1kph just by changing position. More if it is windy.

I assume the poster meant aerodynamic optimisation of the bike itself (eg. aero wheels, aero saddle post, etc).

Riding position obviously makes a huge difference.

The issue is that a lot of the aerodynamic frame advances only work in ideal laminar conditions. However wind is gusty, there are trees and other obstacles next to the course etc. In those cases the advantages largely disappear as Hambini has shown.

I'm not sure what testing Hambini has been up to, last I saw him he was calling for the death of Damon Rinard (who is a really nice guy, by the way! and great cycling engineer)

However I have plenty of first hand field testing data showing that this is very obviously not true, as do hundreds of other people. We ride in the real world with power meters and timers and we can detect these things even in gusty real world conditions.

Just two examples:

http://www.trainingandracingwithapowermeter.com/2010/10/chal...

and

https://betterbicycles.org/science/speed/validation-of-bicyc...

> I'm happy to run through some acceleration scenarios if you like.

Yes, please continue! I'm digging your analysis.

I know nothing about typical bike timings, but I was struck by that. Does it really take 40 minutes to go 1 km at an 8% grade? Would it be faster to get off the bike and walk? When you're not rolling, you don't have to output power to fight your own weight trying to roll back - the friction between your shoes and the ground counteracts that. (I assume a real race doesn't allow you to walk, just batting around thoughts hypothetically here.)

I suspect the parent is referring to elevation, not distance. 1km in distance would only take a few minutes.

One racecourse I know about that has both running and bicycle races is the Mt Washington Auto Road in New Hampshire USA. It is the tallest mountain east of the continent. The top is at 6288ft/1917m above sea level. The road is 7.6 miles / 12.2 km long and the climb is 4650 vertical feet / 1420m.

The footrace has been run since 1936 and the bicycle race since 1973. The road used to be paved only half way and gravel the rest, but it is now largely paved.

Now, the Men's bicycle record is 0:50:38 (2022) and the women's record is 58:14 (2000). The running race records are 0:56:41 (2004) and 1:09:25 (2012).

So, pretty clearly, even at a 12% grade, the bicycle still has an advantage. I'd say this is still true even though the bicycle race consistently attracts US Cycling Team and other international class competitors, and the running race seems to less frequently attract that caliber.

[0] https://en.wikipedia.org/wiki/Mount_Washington_Road_Race

[1] https://en.wikipedia.org/wiki/Mount_Washington_Auto_Road_Bic...

Very interesting information, thanks. The sibling comment pointed out that the parent probably meant 40 minutes for 1km of elevation gain, not linear distance, which makes sense too.

Maybe I'm just trying to justify my own struggles where it's faster to walk the bike up any significant grade :)

YW. You might be using too high a gear, so pushing too hard, which will definitely slow you down going uphills.

In general for reasonably flat riding, you want to be spinning at 80-90RPM. Most cyclists I see are spinning much slower, so pushing much harder. Think in terms of lifting a weight. You might be able to lift 10kg only six times on some motion, but you can likely lift 1kg far more than 60 times with the same motion.

I also have a lesson from Mt Washington. I was an unranked teenage amateur bicycle racer doing ok, but only using bicycle racing as training for ski racing. I'd won a couple regional-level hillclimbs and was looking for another race and someone said "call this guy". I did, and got told about the first Mt Washington bike race. I had no idea what gearing to use, so got the lowest granny-geal cluster I could find in a day. I got to the race and among the small crowd were four guys from the US Cycling Team. I wound up finishing 3rd, only 4min behind John Allis (3-time Olympian) 1h:15m time and 4sec behind 2nd place. I had by mostly dumb luck out-guessed everyone on the gears (neither my conditioning nor my bike was close to their class). The next year Allis came back and won again knocking 14min off his time, presumably with a lower gear cluster.

So, I'd definitely take a look and see about using lower gears...

You're forgetting the effect of exertion on the rider under heavy loads like climbing.

I've ridden heavy bikes, and I've ridden light bikes. Light bikes feel better, rotational weight mattering more than anything else.

They’re not- 300W of effort is 300W of effort, it doesn’t have a bigger impact if the bike is heavier or not.

I wonder if that's really true on hills. Most people ride hills with more effort, pushing down on one pedal at a time. The bike speeds up and slows down much more with each pedal stroke. Compare to the flats where you have a smooth stroke and very consistent output.

I could see all the mini accelerations adding up to a much larger energy expenditure than would be indicated by a spherical cow in a vacuum.

Eh, it's really quite small, unless you have stupid heavy wheels (meaning, that the wheels are a significant percentage of the mass of the entire system).

If the mass of the wheel is 100% located at the rim, the energy goes 1/2 into straight line energy and half into rotational. But -- if you slow down, you don't lose that energy, it just redistributes to gravitational potential. The flywheel effect from heavy wheels may actually help, as it tends to smooth out pedal strokes.

The energy to go up a hill is just mgh - friction. Some cadences are less efficient than others (e.g. for me, standing is more power but lower efficiency), and bikes that are too stiff may not help you get the best rhythm.

In a totally unscientific test -- I've got a 12kg Aluminum gravel bike, wide tires, rack, fenders. I've also got an 8kg carbon racing bike, skinny tires, aero rims, etc. They have similar riding positions (reach/drop), though the gravel bike has a wider seat, which is better for one climbing cadence. I usually ride the gravel bike these days, because comfort.

Two weekends in a row, I did a 12x rep climbing workout (2.5 hours), one on each bike. First weekend, Road bike. It felt _fast_. Quick, lively, accelerated from the stoplights on the way to the hill. Second week, back on the gravel bike, grinding up the hill. Total ET difference: 5 seconds.

Sure there are differences.

Rotational inertia matters extremely little for bike feel compared to the overall weight of rider+bike. The torque required to accelerate a wheel by itself without any resistance is minimal.

You have any sources for this? Not trying to call you out but I am generally curious. We know on a car that rotational mass makes a huge difference but a car is continually accelerating and has a constant type of locomotion that is very different than a person riding a bike. In addition the rotational mass of a bicycle wheel is much, much larger diameter comparatively to the total weight of the vehicle (compared to a car) and provides a gyroscopic effect that is critical to the way a bicycle rides and stays upright. I would expect if we could make impossible light bicycle rims and tires the bike would have trouble balancing and feel like shit and also decelerate much faster. But surely there is some middle ground that is ideal?

It's first year kinematics. The (first order) math is pretty easy to work out. 1/2 I w^2 is the rotational potential energy, Assuming all the mass of the wheel is at the rim (worst case) I = mr^2, w=v/r, so that works out to 1/2 mv^2, which is the same as the translational kinetic energy. So the 'energy penalty' of rotating mass is 2x. So, a 10kg bike with 2kg of wheels and 100kg of rider is approximately equal a non-rotating mass of 112kg. However, that rotating mass gives you 2% more kinetic energy to trade for wind drag, gravitational potential, or other friction. So, not much.

A bike's does not require gyroscopic effects to stay up -- there was an experiment with counter rotating wheels (to cancel the gyroscopic moment) that was ridable. The actual stability depends on the geometric and pneumatic trail, flop, weight distribution on the steering axis, and a few other things.

There is a middle ground that people have converged to -- Somewhere in the range of around 600mm bead seat diameter and an inch or two of tire. (26"->700c, 25->50mm width covers most of the biking world.)

Sounds like those crazy 650B people then have been right all along!

You can test this yourself. Flip your bike upside down, shift it into a gear that you use to accelerate, take a torque wrench with hex socket and put it in the left pedal socket on the backside of the crank like you would when installing it. Then test the torque required to get the wheel moving. You would find that these numbers are minimal.

Also gyroscopic effect has very little to do with the bike staying upright. The reason a bike stays upright is because of the trail interaction and camber thrust. When the bike leans left, camber thrust of the tire makes it turn left, which moves bottom of the bike to the left, correcting the initial lean, while the geometric trail prevents the tire from turning left completely.

Interesting!

I am not sure this is true - I actually prefer a heavier bike for general use. If I was racing up hills or still doing cyclocross then light as possible would be best (and of course also me being light as possible being the biggest factor). I have ridden a lot of bikes and the ones that "feel" the best have a moderately "heavy" frame designed to be fairly stiff but not crazy stiff (heavy meaning at most the light end of a steel framed road bike) with extra sturdy rims that are also as light as possible. By far the biggest effects on "feel" however tend to be tires (skinny tires suck) as you can fine tune the pressure to the surface. And of course quality bearings in the BB and hubs can make a huge difference but once you get to a certain middle level they are all good enough.

When the bike gets too light you feel the effect of bumps and terrain much more and it throws the bike around more (especially if you are "getting light" over said bumps). The lightest bikes also tend to be made for racing and can sometimes be on the ultra super stiff end of the spectrum.

I'm not that old, or have a super long history with cycling. But out of the handful of bikes I've ridden, I def prefer double-butted steel (over straight-gauge Hi-Ten, straight-gauge 4130, 90's aluminum, modern aluminum, modern steel gravel bikes) whether I'm going all-out, or cruisin. And even between 2 double-butted steel frames from different tubing manufacturers made for the same use-case more or less, they've felt different enough to me. At least that's how I felt after having put the same components on two steel framesets, and putting them both through about 2k miles each. One frameset was definitely more enjoyable, while the other felt lacking to the point where I wished it were the other bike.

I have two relatives who have raced bikes in the past at high levels, and both owned stores. One of them was a stronger racer who didn't care about gear as much. The other was still a heavy hitter, but wasn't as naturally talented, and enjoyed the nuances between components way more. He and I seem to agree on things.

I do know that tire pressure and width make a huge difference in plushness, but I still prefer a springier ride-feel from the steel I like, vs. even a modern steel gravel bike with 42's with lower PSI. I had such high hopes for that ride, but man, it just felt kinda muted and leaden, and I missed my steel road bike.

But yeah everyone will have their personal prefs, subjective interpretations, and theories about what works for them and doesn't. Gimme that springy lightweight steel any day.

You would probably love late 1980s high end touring bikes then - they are basically the best of the best of steel

I'm a former racer too and this constant equipment arms race and arguing is just so fatiguing.

People can argue about analytics around equipment till pigs fly. It's all still just an order of magnitude smaller than the differences between being fit and not fit and a stronger rider versus a weaker rider or a coached rider versus un-coached rider.

The sport has separated into riding enthusiasts and equipment enthusiasts and the bike companies have completely brainwashed equipment enthusiasts.

Your times don't make any sense either... 8% for 1km takes vastly less time than you're talking about at the power levels you're talking about. You're probably off an order of magnitude there. A rider with an FTP of around 300 will probably climb closer to 10km @ 8% in 40 minutes.

Nothing is more tiring than being at the start of a race and there's someone with a $10k+ bike and a gut talking smack about bikes to someone everyone else knows is going to win the race and the guy with the $10k bike is getting dropped & pulled from the race. One person spent all their time on training and the other spent all their time researching & buying equipment.

You are right I had the gradient off by 10x, sorry that should have been obvious, it has been a while

Actual time savings of 1kg of weight reduction: 1 second

And personally I've used aeroweenieing to podium in a cat 3 road race, and my wife has set state records and won pro races. You can make fun of fat guys doing a professional job if you like but it isn't just them.

If spending lots of money to win a Cat 3 race and knowing you did it with money and equipment instead of fitness and smarts is OK with you more power to you. But if it means thousands of dollars spent on a race that likely paid < $50 to the winner the whole thing can also look ridiculous too depending on perspective.

This isn't really funny, it's a fundamental problem with cycling as a sport that limits who participates in the sport and hurts the sports ability to find and develop the best riders. It seems particularly bad in the US. Rules which helped control the equipment arms race would be good for the sport at the competitive level. Many promising athletes never try the sport because the costs are so prohibitive. On top of that in road racing if expensive equipment raises the speed of everyone in the field it accomplishes nothing other than increasing the risk of severe injury as speeds go up.

If someone made $10k shoes that gave a competitive advantage in soccer or basketball, or a $10k baseball bat that offered significant advantages, etc.. that equipment would very likely be outlawed right away. Cycling has let everything get very out of control. Baseball obviously has already banned lots of bats that offer competitive advantage, whether it's banning metal bats after a certain level or limiting the power of metal bats below that level.

In almost every hobby there are people who get enjoyment from choosing and buying equipment and others who just want to do the thing. Look at people with massive collections of beard games they never play, people with any cameras and lenses but little output, etc. It's fine. Let people enjoy their hobby however they like.

Keirin bikes need to be built out of approved frames and parts, I’m surprised there isn’t a road racing category with similar rules

Its always easier to try to buy your way up the chain than putting in the work. And when you are not actually a pro it often becomes a social novelty of its own (and within reason one I often enjoy myself). The end game for me in all things like this is that when I actually become a sort of expert in the gear choices I realize that often the middle ground items are sometimes the best - pricier things are often better but there are huge diminishing returns and sometimes the simplest item of decent quality is actually the most functional.

> The sport has separated into riding enthusiasts and equipment enthusiasts and the bike companies have completely brainwashed equipment enthusiasts.

I'm NOT a former racer but I've cycled recreationally (probably an average of about 30 miles a week, give or take) for over 20 years.

When I first got into road cycling I nerded out on gear. Back then that meant skinny tires, carbon fiber, big bucks. I felt reallllly cool.

As I've gotten older I stopped caring about what's cool. Like, in cycling, but in pretty much everything else too.

I had to move recently, and ditched my road bike but kept my "cyclocross" (as it was called at the time I bought it) bike, since I wanted something more flexible and comfortable. It ways weigh more, and I ride on big honking tires with hefty tread.

I tracked my (solo, non-drafting) rides and I'm slower... by like, .5 mph.

I have no doubt that all the gear nerds out there know what they're talking about, and these data driven fads are real improvements, but the margins have gotta be smaller than most of us weekend warriors should realistically ever care about.

At a certain point you gotta ask yourself why you're even into the sport - either you think you're gonna win something, and then this is your life (and every advantage is worth it), or you're in it to ride with buddies and enjoy the feeling of moving through space. If you're in the latter category, and you aren't getting dropped, obsessively optimizing gear isn't actually gonna make your experience any more fulfilling.

You are assuming that rider can output X watts continuously. This is not how humans work. Riders have different profiles in terms of torque vs rpm from their legs. A lighter bike means that a rider is outputing less torque, which he/she can sustain without downshifting to a lower gear, leading to overall increase in time not only during the climb, but also how much energy the rider has left in the tank after the climb for the rest of the course.

There is actually very little difference between a cyclocross bike and a lightweight gravel bike. Slightly lower BB, slightly longer wheelbase, sometimes slightly different headtube angle, flared handlebars. Actually the first gravel bikes were rebadged cx bikes. You can race cx with a gravel bike and race gravel with a cx bike. The rider makes most of the difference.

And you can do fine in a road race with a gravel or cyclocross bike! Just gotta put appropriate tires on.

You have just proved you haven't rode a cyclocross bike. Since those bikes' center of mass is higher than the road bikes it is really "nervous" on high speeds for example long descents.

I won a criterium once on a cyclocross bike while waiting for my team supplied road race bike.

That so called nervousness is greatly overstated. I think this is a US thing actually.

But crit races are not like coming down from Stelvio kind of speed where nervousness counts. Crit races are exactly like cx races but on asphalt or at least where I'm in Europe ;)

I rode my cyclocross bike in the Swiss alps for months while waiting for my custom road bike. It was perfectly fine descending mountain passes.

As I said, that so called nervousness is overstated because people overthink it. BB height matter but for the most part we intuitively and inconsciously accounts for it and adapt. Also the difference is minute, from a 5 mm to 15mm. It is not like we switch from a road to a tall bike either. And guess what? A tall bike is pretty easily rideable, there are even people doing offroad on them.

A lot of people do not size their cross bike right - they ride a top tube length that is too short. Maybe this also helps with tight turning radius (which could be an advantage during a cross race).

not true - the "nervous" feel is because people also tend to ride cyclocross bikes that are shorter (top tube length). There is no reason a cyclocross bike cannot be designed with the higher bottom bracket AND a longer top tube - I never understood why the frames were designed like this in the first place (maybe for weight savings?)

edit: Realized it is for turning radius

I always raced CX bikes that had the same top tube length as my road bike but usually with a 1cm shorter stem for a slightly more upright position.

Cyclocross bikes also have higher bottom brackets

That is what I mentionned by "Slightly lower BB" for the gravel bike, just stated in the opposite direction.

It doesn't matter much anyway and CX bikes from US brands had already started lowering the BB of the CX bikes because US courses designers are usually less keen on putting off cambers section than euro courses designers.

Sorry somehow missed that.

The explanation I heard for the traditionally higher brackets is that it facilitates quicker turning. Is there truth to this or is this more of a marketing thing?

I think it is a mix of many parameters and the main one was that when cx was invented people were using toe clips with straps, albeit looser than on the road and they would hit the ground until the rider has put his foot inside when the bottom bracket was too low.

The rest is mostly the ability to pedal in the corners without clipping a wheel, which help maintain and feel grip, tradition and also to help on the many off camber sections the courses used to have.

I think quicker turning has never been the true reason imo.

Larger road frames are designed to accommodate longer cranks and their BB drop approaches that of traditional CX which is itself dropping to lower heights as fashion changes.

> You can race cx with a gravel bike and race gravel with a cx bike.

Sortof. The key defining difference is that a cyclocross bike meets the UCI rules for cyclocross, while a gravel bike doesn't. In a sense, the gravel bike trend is the result of consumers rejecting the UCI's definition of what an off-road-capable drop-bar bike should be.

A gravel bike is perfectly allowed by the UCI. You just have to mount CX tires (width 33mm) on it.

So much bicycle acronyms and initialisms makes for a challenging read for the uninitiated (like myself)! I've researched the terminology and happily share in hopes you too will find it useful:

1. "lower BB" references a lower bottom-bracket, the part that holds the axle to which the cranks attach.

2. "CX", or cyclo-X is short for cyclocross, which is a style of bicycle race which takes place over varied terrain conditions such as pavement, wooded trails, grass, steep hills and obstacles requiring the rider to quickly dismount, carry the bike while navigating the obstruction and remount.

https://en.wikipedia.org/wiki/Cyclo-cross

https://en.wikipedia.org/wiki/Cyclo-cross_bicycle

The cyclocross bikes appear similar to road racing cycles, the major differences between them being frame geometry, and wider clearances for cx bikes to fit larger tires and generally still function after accumulating large amounts of mud and other debris.

edit: Thank you @jerrycrunch! I've incorporated your bb info.

Bottom bracket, the part that holds the axle to which the cranks attach.

Sorry for that. I am a hardcore cyclist, I don't always realize that people are not as accustomed to the terminology.

Geometry is actually probably the big difference - cyclocross bikes are designed for small repeatable courses often with tight turns and the need to carry the bike on your shoulder. A slightly lower or higher BB height would probably work well for either - it is the ratio of total height vs top tube (so height vs length of the frame) that really defines cross vs gravel. Cross bikes will be taller and shorter (length wise) to have shorter turning radiuses and slightly lower weight at the expense of long term rider comfort and stability at speed. Gravel bikes will be longer and have worse turning radiuses but slightly better stability at speed. You can see the same thing with cars. A shorter bike (just like a short wheelbase vehicle) will also have better approach angles relative to its height.

That being said depending on your leg length to upper body torso length you can of course size a cyclocross bike up or a gravel bike down and achieve sort of the same effect. In my opinion these types of geometry questions do not come up nearly enough in relation to the rider, however, as someone with a very long torso is going to be quite uncomfortable with a bike with a short top tube even if the "size" of the bike is correct for their leg length / height. And of course the opposite can also be true. Ideally we should be sizing and matching frame geometry to the persons geometry regardless of the intended use case of the bike.

I think you’re overestimating the ability of most of your competition. As a former racer, you probably have leftover power and you know how to race. It was less about your bike being “light” and more about your personal ability.

Their "giant heavy gravel bikes" were probably a few pounds heavier than your CX bike, but your dad belly made you like 10 or 15 pounds heavier. Heavier people go faster down hills. I'm unconvinced that their bikes slowed them down, unless they were also super un-aerodynamic (wide handlebars, attaching water bottles to the forks, upright positions, flappy wind jackets)

To quote someone I met thru-hiking: "Food is lighter once you eat it."

Or in other words, subjectively, weight on your body doesn't cost as much as weight you're hauling whether on your back or on your bike.

Nope, I can't explain it either, but I've got over 3000 miles hiking/backpacking and it holds true. Can't measure it, didn't try, but I can assure you that feeling worn down is roughly equivalent to being worn down. Getting a pound of weight off your back and into your belly (or the reverse when you fill up with water) is noticeable.

Could this be true for walking but not for biking? The human body is adapted to carrying its own weight while walking, but not adapted to carrying significant weight on the back. But while biking the body is supported by the bike, and largely only the legs move.

That’s been tested and it’s objectively not true from a physics perspective.

That said, weight isn’t as big a factor until you go uphill, which is why you’re seeing the trend to more aero instead of lighter weight bikes.

What you’re describing, however, is the simple effect of eating food replenishing your energy.

The parent did say "subjectively", but I think there's a case to be made that this is even objectively true:

A pound of food carried inside your stomach is located very close to your body's unloaded center of mass. That same pound of food carried in a backpack is placed further away, creating a torque that your muscles need to work to counteract. So it very well may be the case that carrying the food on your back has a slightly higher energy cost.

It's possible that the additional energy is negligible, or at least low compared to the "subjective" increase in perceived exertion. But I don't think the idea is entirely unfounded.

This has been tested and, no, the location doesn’t make a difference to the necessary power output on a bike. Weight is weight as far as the system is concerned.

Another thing that might come into play is simply holding the backpack on your back. If you put that same weight on a saddle bag or frame bag, your power output won’t need to change but you’re not constantly carrying it physically on your back.

It probably is functionally lighter, too. When you walk, your body doesn't slide smoothly along the ground - it wobbles up and down and back and forth. The way most people walk is optimised so that the torso does the least amount of wobbling, but if you add a heavy backpack on that person, it will be moving back-and-forth. Technically, that backpack isn't heavier than it it was in a person's belly, but it does move around more and cost more energy.

If most people are there just to finish then comfort should be more important than speed. In that case big tires and more relaxed geometry makes perfect sense.

Are gravel bikes heavy now? From what I remember (admittedly 10 years ago) "gravel" bikes were pretty much cyclocross bikes to begin with just with slick tires.

I sold my fancy lightweight cyclocross bike around this time and built myself a fully custom bike with a hodgepodge of parts - I wanted something that looked a bit vintage cool and also not as stealable so I went with the pinnacle of late 1980s touring frames (steel) which is obviously not light but not all that heavy either. Bought lightweight 29er rims + 35C quality touring tires, wide flared dirt drop bars, nice 9sp bar end shifters with a triple crank up front (9sp being my favourite in that you can still friction shift it easily if needed and the bar ends can easily switch from indexed to friction at the flick of a switch). The thing absolutely flys on gravel, pavement, dirt roads, shitty sidewalks - basically is my do everything bike for general use from groceries to exercise.

I think he's including fat bikes in that ranking, actually competitive gravel bikes are not heavy at all. I know the Allied Able and Echo have won some races and although it comes with slightly heavier tires it's not too far off from a road bike https://alliedcycleworks.com/collections/able https://alliedcycleworks.com/collections/echo

Anything that's made of metal symply was never competitive to begin with

Yeah that sounds about right. Probably people are doing these races on what they already have (fat bikes and mountain bikes) which are obviously not ideal at all. A gravel race shouldnt have any drops or major obstructions so why would you ever want shocks and whatnot?

My opinion is that general use "road" bicycles peaked in the late 1980s and everything we have now are just modern re-inventions of that. A touring bicycle is basically just a gravel bike and also the ideal commuter, grocery getter, and fire road bike. With some "sport touring" bikes being criminally underrated (and also some being more just cheaper road bikes)

Mountain bikes on the other hand have improved tremendously and of course any bike designed for racing (road, cyclocross, etc) has as well.

A gravel bike is the perfect commuter bike! At least if you're not going electric.

Almost as light and fast as a road bike. But a bit more upright riding so it's more comfortable. Wider and more treaded tires means tram lines, pot holes, curbs etc. are less of a problem and can handle rough surfaces and not just asphalt. Mounting points and wider forks allow for mudguards / fenders so rain is no problem. The wider space allows for studded tires during winter. Also easier to mount panniers / luggage carriers to carry stuff home from the stores.

While I love my road bike for long rides on the weekend, I use my gravel bike daily. And it also allows me to go places I cannot go with the road bike, without having to go all mountain-bikey.

Btw, for road biking we often compare aerodynamics using "wattage per dollar". It can be surprising what then should be the first things to improve.

Gravel bikes are good commuters, if you like drop bars. Many commuters prefer flat bars for the more upright riding position, which allows for a better field of view for misbehaving drivers.

You still also have the classic problem that higher end bikes lose all the commuter friendly features. Carbon forks and frames often lose mounting points for fenders+rack. The marketing vision of a gravel bike is someone expecting to get muddy and who isn't trying to stuff a laptop into a saddle bag. Durable, maintenance friendly choices like threaded BBs and easy cable routing go away. You're stuck with heavy bikes with poor gear ranges, super low end components, cable brakes, etc.

I agree but there are exceptions. My carbon bike (from GT) has bikepacking mounts on both the frame and the fork. Mounting fenders wasn't a problem either. It also has outside cable routing but not a threaded BB.

I think Canyon is selling bikepacking gravel bike as well (Grizl). There are choices, you just need to look for them. It's true that these days availability is a problem but it's a problem with everything cycling related.

Drop bars can be set as high as you want. There are even off road drop bar bikes built with stems looking like goose necks to put the bar high enough (see example in the link). It is more about the position in which you want to put your hands/wrist that matters.

Gravel bikes are sold in many different kinds, and different materials. Steel, alu, titanium, carbon, you name it. They are also build with different use in mind. Some are "racing" gravel with many lightweight high end components, other are made for bikepacking with provision for fenders, front and rear racks and usually more common standards. Those are commuters friendly.

Link: https://2.bp.blogspot.com/-hVZNsMpWmxk/V9rqVdtLBHI/AAAAAAAAQ...

I cut my stem long and run my bars high due to a back injury.

It does mean that I essentially had to learn how to build my entire bike from scratch since noone builds a bike that way, but I'm happy I did.

For what its worth there are custom builders that do bikes in any geometry. There are also a number of small bicycles companies that may not have a shop in every city but that provide bikes with various kind of geometries.

Eventually I may do that, but for now keeping the stem long has been a good fit for me.

To clarify for some readers, you really only need super tall stems for major downhill sections and drops. Standard gravel bike geometries are just fine for most singletrack, even on gnarly terrain that most riders would balk at. Brake levers that are angled inward and spaced properly matters much more for instant responsiveness and precise turning control on hazardous technical terrain.

> You're stuck with heavy bikes with poor gear ranges, super low end components, cable brakes, etc.

Hmm, not my experience at all. At least the market here there are no "cheap" gravels. For around $1k-$1.5k (which is the cheapest gravels available here) I've gotten hydraulic breaks, Shimano GRX groupset, an OK weight etc.

Those prices seem low these days if you want any availability. All I'm seeing around me is $2-2.5k minimum for the same specs (higher end = carbon frame).

My steel gravel bike was built with bikepacking in mind, so it's carbon fork was revised after the first year to have those mounts for exactly that reason (Niner RLT Steel).

Modern drop bar shifters have an upright position though?

Extra wide dirt drops with the flare are best in my opinion for everything. They are not like the oldschool flared bars where they flare up and then out - they are totally flat at the center (and wide at the center) and then the drops flare outwards (the drops are not purely vertical). You combine this with an extra long stem (for more upright riding) and you get the best of all worlds. You can ride them like flat top bars with multiple hand positions in the center and there is tons of room for mounting lights or a beverage holder. You can install nice big fat shifters with comfy rubber hoods so you can hold via the hood itself or place your hand around the top of the drop and still brake. And then of course you can place your hands deep in the drops or at the very bottom of the drops.

I'm in agreement with almost everything except the tires. Unless your commute has a significant portion of rough surfaces, you definitely want to use some road tires. Not the super skinny ones used on road bikes, so you don't have an issue with tram lines/pot holes/curbs, but good reinforced road tires (so you don't have flats when going over glass/nails/whatever).

I've been commuting daily on a mountain-bike (chosen for the comfort of a full suspension and the braking power of disk brakes), and switching from the factory all-terrain tires to road tires about 2/3 the width has been a huge improvement: a lot less rolling resistance, and a lot more grip, especially when it's raining (despite less width).

I've commuted on a roady, a steel big tire bikepacking bike (basically a hardtail MTB) and now a gravel bike. I'd say the tires on gravel bikes tend to be the best compromise between comfort you get from a big volume tire, and the speed of a road or commute tire. They can run pretty high pressures, which is the biggest factor for rolling resistance, and they're pretty skinny relative to MTB tires.

For me, the minute rolling resistance tradeoff between the gravel tire and a commute tire is worth it. The road and bike network here kinda suck for smoothness, I'd rattle apart if I ran a road tire.

Thanks for the feedback! I've not had the occasion to try gravel tires.

For me, the main reason to use road tires is grip on asphalt, not rolling resistance improvment. On your commute, you may need to stop in an instant, and more grip = quicker stop = safer (I've had a few close calls, especially downhill under rain).

Obviously, that's also dependent on your regular commute road condition.

Braking is the main reason I love gravel tyres for commuting: their increased size means a larger contact patch which directly translates into a shorter stop (as stopping on skinny tyres with disc brakes is typically traction-limited).

The tyres on my gravel bike look just like fat road tyres: no knobs.

Have you considered tubeless? I hear that gives the RR benefits of high pressure but at lower pressures.

There are slick gravel tires. The author of the article sell some of his own brand Rene Herse. They are made by japanese brand Panaracer who also produce slick and treaded gravel tires under its own name and for other companies.

Slick large volume gravel tires are also sold by most bicycle tire brands. Most of them are tubeless compatible which remove the need for reinforced heavy tires as any puncture usually seal itself thanks to sealant.

I've also commuted for years on thin cotton road tubulars so it really depends on the kind of roads your are riding on. But having high volume will certainly improve comfort and also allow for better grip in the wet and better ride when the bike is loaded which is often the case if you are commuting.

Panaracer Pacenti's have been my goto everything tires for a few years now. Excellent hybrid tire.

Quality "touring" tires are amazing for this. They have a little bit of tread in case you need to do some dirt but very minimal. They are extra thick rubber because nobody wants to replace a tire if they are trying to bike 3000 miles over multiple months and they have low rolling resistance. They fit most bikes and come in very useful sizes like 35 or 38C. Schwabe Marathon is the classic choice but there are tons out there!

I agree, except on the electric part. Where I live e-bikes don't assist over 25/kmph, and I'm always above that... until, my ride home. Which is steep hill, and I'm tired, and I just want to go home. As an all-rounder it's been the best bike I've had yet, I can do just about anything with it. Very utilitarian.

I ride a heap, I ride MTB, commute and also a gravel bike for fun, so I feel no shame getting that e-assist on the commute. I don't need it for the fitness, I'm just getting to work!

One of the big benefits of a gravel bike is indeed the tires, they can be tubeless so no more annoying pinch flats, and they can be run at really comfy pressures depending on your personal preference.

Depending on the bike/motor you've got, something like this can be very inconspicuously added to your bike to get past the 25/kmph limit: https://planet3.bike

I've one on a Specialized Levo and it works great.

That's a great solution, I knew about the method for circumvention being the magnet pickup but I've never seen a specific defeat device like this. That's really clever.

Sounds like you also live in Oslo? At least the nice thing is that I don't get that sweaty on the way to work..

Not sure if you misunderstood my comment? I'm all for electric bikes (my GF is getting one today actually) and how they enable many more people to bike. I love seeing parents bike their kids to school on this big ebikes, zooming past hundred cars in a gridlock. But _if_ you're not going electric, a gravel is a great bike. If you're going electric, most of the problems a gravel solve aren't really a problem.

Oh I didn't think you were detracting from e-bikes, I just think that an electric gravel bike is worthwhile as it's still a fantastic formfactor for commuting, especially if you still want to use it non-electrically and out on rougher terrain (where rougher can be little bits of dirt or rough road on your commute).

I am actually in Australia, which has some surprisingly hilly places!

Ah, I see. I've never tried commuting on an electric, so I just tried to say that my advice from my knowledge only applied to "acoustic" bikes. But great to hear that gravel e-bikes rock as well!

I bought a steel frame touring bike for commuting and I think it's pretty much perfect mostly because the steel is springy, giving a pretty comfy ride.

Cutting the bike weight or tuning for aerodynamics seems kind of pointless because I have one or two panniers on board to carry the stuff I need for work (towel and dopp kit, change of clothes, lunch, laptop, etc...). Also, exercise is one of the reasons I'm choosing to commute by bike so having to work a tiny bit harder isn't necessarily bad.

"Touring" bike is basically just a gravel bike from the 1980s. There are also 1980s "sport touring" bikes that are similar (less specifically designed for long term touring with tons of rack mounts). Some of these are more just like affordable general use road bikes but the better "sport touring" bikes are the most underrated bicycles out there IMHO.

The Dutch style bike is almost perfect for commuting, but for badly maintained roads I would occasionally want one with MTB suspension and tyres.

Yes, I've always wanted a "rural bike" to match Dutch urban bikes: upright posture with a comfy seat, fenders, baskets, a kickstand, IGH/belt, but wide tires and maybe even suspension.

Marin Muirwoods RC came close, but was overpriced for a banger bike.

Dutch style bikes are perfect for casual city riding, sight seeing and well, riding slowly. Usually when you are commuting and you have more than a couple kilometers to ride you want to do it faster. Dutch omafiets are really bad in term of aero.

Would you happen to know the age at which Dutch commuters (shopping) start to give up cycling? Do people regularly cycle past 90?

I don't have that exact figure, but the 65+ age group has a higher bicycle mode share than 26-45 and 46-64: https://www.researchgate.net/figure/Bicycling-share-of-trips...

The oldest age I've found is 75, and they still rode 2x per week in 2011. http://www.aviewfromthecyclepath.com/2011/02/who-cycles-in-n...

I think it's pointless to lump everything together as "commute" - sure, if you're lucky and need to go only like 4km without hills then basically every bike will do - but no, I don't want to do 12-15km one way with that, just because I can probably save 1/3 of the time (also gravel vs road)

A Dutch-style bike is perfect for Dutch-style commuting: riding maybe three miles max to the shops or public transit on a high-quality network of bike infrastructure where you won't be bullied by drivers for riding at 8-12mph.

Atrocious US land use & infrastructure makes this less practical for many trips in the US, where destinations are widely spaced to allow for free/easy car parking and evasive maneuvers are often required for safety, and steep/off-road shortcuts are often useful to avoid traveling miles out of one's way on a network of arterial roads designed for fast & easy car travel at the expense of everything else, including human life. A gravel or hybrid bike is better suited for this sort of riding.

umm, hate to break it out to You, but... there's no such thing as a "perfect bike". This is why we have Rule #12 amongst the Velominati, the Keepers of the Cog. "The ideal number of bikes is always n+1, where n is the current number of bikes"

Everyone's commute is slightly different and while I use my gravel as a commuter just like You do, there's always the matter of personal preference.

What if You prefer to ride in regular clothes and "style" is a thing? Those dutch bikes someone mentioned a few comments ago are great for that.

What if You're riding through dense traffic / cityscape half of the time? A narrow bar fixie perhaps?

I like being able to get some exercise while commuting as well, but that's not necessarily true for everyone.

Of course! But I just wanted to give gravel some love! And spread some awareness of their existence.

I think most casual bike riders don't recognize them as a separate bike from road bikes. So they think it's either a dutch styled bike or a road bike, and if neither fit they end up commuting by car or so instead.

I agree. I ride a Niner RLT Steel with drop bars, 1x10 gearset, 650b wheels, and Panaracer Pacenti tires.

I specify those things because my Bike of Theseus went through MANY variations before I got it to where I was happy!

From a money perspective, there is no reason to buy an analog bike for commuting anymore given the current selection of ebikes, and even more so, aftermarket ebike kits like Bafang. You can buy a single speed beach cruiser for $200, add $1000 BBSHD kit that comes with a battery, and basically get everywhere faster than a top of the line aero road bike.

Well other than that with $1,200 commuter/cx bike you are getting much better quality kit, and are still getting a load of exercise.

Most ebike motors have different power modes. My wife has a beach cruiser bike set up with BBSHD with 5 power modes (custom programmed) depending on what she wants. Lowest power mode makes it feel like a regular bike because the added power compensates for the extra weight, mid power modes provide varying level of assist, while the top power mode gives you 30+ mph on throttle alone.

With this bike, she can either get exercise, or commute without pedaling at all.

Kit doesn't really matter when you have that kind of power, weight of the frame, wheels, e.t.c doesn't really matter, and you don't need gears - single speed setup is more reliable, with a thicker single speed chain that can handle the additional power. The only upgrade that I did on hers is just bigger 200 rotors front and back, which with mechanical brakes work totally fine for the weight.

> the fastest riders in the 200-mile Unbound average 20 mph (32 km/h) across the Flint Hills of Kansas.

Let’s not forget that the most important aspect of averaging 20mph on grave roads: drafting, low body weight and high fitness.

If you watch footage of the unbound gravel race they mention, the winners are with a group of riders until the very end.

The fastest riders are professionals sponsored by the companies trying to sell you this aero gear.

If you want to ride faster ride in a group, find your ideal body weight and spend money on a coach. Only then spend money on bike parts beyond the basic lubricated chain, correct tire psi, etc.

Personally, I'd change the order. Coach first, body weight second.

If there's one piece of equipment to buy first & ASAP, it'd be a powermeter and something to display the readout on.

Riding in a group is of course great, but first You got to have the legs to catch up and then the body weight / metabolism to keep up. Having the core / flexibility to be able to spend hours in somewhat aero position doesn't hurt either.

It always makes me laugh to see slightly overweight people on carbon frames. Having a few kilos over myself, I always thought I'd rather spend money / time / effort losing 3-4kg of fat, rather than mulling over how to shave 100g off of the groupset or 300g of wheels weight...

> but first You got to have the legs to catch up and then the body weight / metabolism to keep up.

Not just keep up, if you are riding in a group you need to be fit enough to take your turn on the front where you aren't draughting (at least if the group you are riding with is your team).

The actual team dynamics of professional road racing are fascinating, much like F1 they'll often pick the strongest and expect everyone else to support them.

yeah, I've never really been into group riding / drafting on a competitive level. I'm mostly trying to avoid it, actually (more of a self-supported racing kind of guy).

Where I train (Paris, polygone de Vincennes) there are quite a few groups riding together, but not sure they'd switch places. I guess it depends on why You do what You do.

In my case, if someone wants to ride behind me, I don't mind (other than that it makes me a bit more careful when passing someone / turning corners). I'm there to work on my power output or cadence, not to get KOMs on Strava segments ;-)

Yeah but carbon gives you cred, and basically _buys_ you speed. Losing weight is effort.

Sarcasm over, one of the funniest cycling stories i ever encountered. My work had a little low-key "bike club", a few guys cycling on warm evenings. One of the partners was a key member so over time non-bike guys started wiggling in for networking purposes.

One guy, with no clue how to ride, drops 2k++ on a full carbon bike, high end components etc. Cometh the first hill, and we find ourselves waiting at the top. 2 mins, 5 mins, finally 10-15 mins in one guy turns around to check up.

The carbon bike cyclist figured how to shift up, but didn't know how to shift down, and was trying desperately to climb in a downhill gear.

I quote your sarcasm.

> Losing weight is effort.

I knew a guy that was training to run an amateur marathon in under I don't remember which time. He went asking to a coach and came back with a long list of training exercises and runs or, the coach told him, lose 3 kg. He lost those 3 kg.

oh, that's a good one. Explaining how brifters work never gets old :-D

On a more serious note, I don't really see the appeal of biking as a social / networking sport. Yeah, we do have a sort of a bike cabal at work too, but if I'd like to network, I guess there are much more efficient ways to do that. Biking as a sport has quite high barriers for entry both in material and in getting fit enough to be able to at least reasonably keep up.

The sad thing is that $2k barely gets you a carbon frame with low end components now. A mid tier bike is maybe $5k, and high end can easily be more than $10k.

Personally I really don't get why anyone would pay $10k for a bike. Amateurs won't benefit nearly enough to make it worth it, and pros are of course sponsored.

It was 2k GBP so more like 3k USD but point stands. It wasn't a good bike.

I think semi pros are possibly the main audience. A friend is into endurance events and he just dropped something like 2k on a titanium frame.

There's a difference between weight weenie carbon and using carbon to improve ride feel and aerodynamics. I've got an old bike made out of Reynolds 853 steel that's lighter than my recent vintage full carbon bike.

The "ride feel" argument is something I quite frankly never understood.

I guess it's because I don't do competitive road racing (more of an ultra / bikepacking sort of guy). When I was shopping for my current frame (Kona Rove), I picked up the steel version mostly for maintenance / mechanical reasons more than anything else. Don't see much of a difference in "feel" from my old aluminium road to be honest (other than what's caused by the different geometry / fit).

I'd like to build up some chinese carbon frame next year just for fun, so we'll see. Maybe I'll change opinion then.

But yeah, I 100% agree that the aerodynamics on modern frames is significantly better. Just not really at the speeds at which I end up riding and with the amount of gear / packs I end up putting on the frame / handlebars.

While the Trek Émonda is as weight weenie as Trek gets, it can provide an apples-to-apples comparison between aluminum and carbon with basically the same geometry, wheels, bars, tires etc. My experience is that the carbon version feels significantly nicer.

For bikepacking, I'm with you: A traditional steel frame (albeit one with discs), nice wide tires to eat up road chatter, and plenty of places to mount gear.

It is subtle, but you will know it when you feel it. Aluminium frames can be engineered to have more flex, and some steel frames can be overbuilt to a point where the "steel feel" is diminished. So comparing any two random frames may not be sufficient to capture the feel.

Also the feeling is subtle enough that the components on your bike can be the larger factor. Tires, crank arms, handlebars, tire pressure, etc.. will all play a factor. Swapping all of your components from one bike to the other would be the best test, but unless your components in aggregate provide a "neutral" feel, it is possible that they could overwhelm the feeling that a different frame will provide.

Carbon frames don't really cost especially more money than a nice aluminum bike any more.

That's it. Same as in road cycling, the biggest air resistance is not due to the bike frame but due to the rider that will have to sit on it. The larger cross section is hard to ignore.

To improve speed, make the bike more comfortable so muscles can be more relaxed. To improve speed further, reduce cross section while maintaining a comfortable ride. For the last few percent, get a suit that sits tight.

All the rest is for those that want to save five seconds over an ironman ride, where group riding is not allowed. But hey, tri bikes do look cool, have fun.

This post feels very dismissive of pro cycling, aerodynamics engineering, and what TFA is about. Any pro cyclist is going to use drafting, a low body weight, and have high fitness regardless if they are racing on gravel or not. An upgrade of only 3% for a pro cyclist could be the difference in making podium or not.

Long distance gravel cycling is a relatively new sport and technology and engineering is still in its infancy. There is only minimal design crossover between a fully aero triathlon bike designed for going 112 miles as fast as possible, and a bike ridden for 350 miles by a top finisher at a race like Umbound XL.

Jan Heine isn’t even trying to sell you aero parts. Maybe tires, a journal subscription, or some nice looking parts, but his brand doesn’t sell aero parts. His website doesn’t even offer the aero fairings he used, nor HS r contact info for the framebuilder that built the bike he raced.

In fact there are already some changes in the way gravel is raced and there have been some waves in recent races. When reaching an optionnal resupply/refill point it used to be the case that if the leading 4-5 riders were calling for a pitstop the whole group would stop and wait for anyone to take food and drinks. Now some riders will decide they carry enough and not wait for those that decided on carrying less and stop more often and some additionnal strategy is being put in place. Also some elite riders are calling for a ban of aero handlebars, at least for the fastest ones who fight for the win, in the ground of safety reason. Many stopped using aero bars to set an example but others despite agreeing on the safety issue will continue to use them until a rule is set in place to ban them because they don't want to give up any possible advantage.

He is most definitely trying to sell you parts. Just not aero parts, and this whole article is partially marketing to tell you a bunch of the aero parts don't really matter, so you should buy his parts instead, and use his tires, etc, etc..

And he of course conveniently ignores all this stuff makes about 1/10th the difference rider fitness makes. He is a very fit/accomplished racer, at least he controls that variable, he does most of the test riding himself.

Unless we’re talking about climbing, weight isn’t _everything_. I would argue that being able to stay in an aero position (go on YouTube, but essentially, get on the drops, elbows in, etc) for longer periods is far more important, these aero gains similarly applies to deep dish rims.

All that said, I do agree with your sentiment that shedding a few bricks is going to be more beneficial than shedding a few thousand on a new bike (or rims!). Hell, you might save yourself a divorce in the process!

Lubricated chains and aerodynamics save you energy in a group too.

I started biking around three years ago. Lots of biking, like 5000-8000+ km a year.

As long as I don't weigh my ideal weight and aren't planning on becoming a machine myself, I have zero interest in spending anything in optimizations which will make my bike a better one. I don't care if it could go faster or be more lightweight, spending 600€ for the bike was enough. The cheapest 30€ Schwalbe tires are good enough; I didn't even have a single flat tire this summer after I learned to avoid driving over blackberry branches.

And I really enjoy it. During this summer, with the extreme heat, where I loved the 28°C in the shade of the woods I was thinking about how much I'm going to hate this fall, and now that it's here, I love breathing that cold, fresh air and smelling the humid forest. The only thing I hate is when there's frozen snow on pavement in the winter.

The only thing I spend money on for biking is quality clothing appropriate for the seasons and accessories like good smartphone holders or bags.

I appreciate your approach but the reason people like optimizations is for speed. The thrill of riding fast is what keeps a lot of us coming back.

Lots of people optimise because they fell in the rabbit hole of optimisation and it became an addiction. Like in every hobbies some people completely lose touch with reality. I've seen videos of people comparing weight of bicycle seats and how to shave like 13 grams of weight of the bike, meanwhile the dude had a dad bod and shaving his torso would have shaved more weight than his $$$ seat

Don't get me wrong, I also love to go down a forest path at 45 kph to the point where I get scared, but I know that I also have to go up again. But going as fast as possible on a horizontal path is not attractive to me at all. If I want to expend energy, I prefer to ride up a hill where I then can have the fun of riding down, even if I have to pedal 20 minutes up to then go down within a minute or two.

But I also recognize that there are those who are already super efficient and want to get the absolutely most out of their gear, even improving it as much as possible, which is really ok by me. I wish I were at that point, but I think I'd first have to go to the gym for that.

There is riding fast and there is riding fast but just a tiny bit slower.

I have a modern race bike, less than 3y old with some but not all of the latest aero features. I also still own my 30y old racing bike that I used to race until 20years ago (it was already old bike then). It stays at my parents place and I ride it maybe twice a year. If you ask any bike reviewer he will tell that old bike is obsolete, feel much slower and make me lose 45s over the course of a 50km ride according to the data given by the manufacturer. If you ask me, sure I feel a difference, mostly in feeling, when I start riding the bike. But after 5 minutes all this is forgotten and I enjoy the ride as much as on my more modern bike. And that bike is perfectly fine surrounded by superbikes in a group ride. Actually I did one this summer with a group that tend to stay together but ride at a fast steady pace until the last 20k where the wait "policy" disappear and people start to attack the climbs at max pace. I ended up in the 5 rider leading group out of maybe 40 and I was totally out of shape.

That old bike would sell for 300-400€ in the second hand market right now. The difference with a 2k and 8k modern bike is much lower.

Ultimately, it's the engine.

Reminds me of this bicycle subreddit where they spend thousands on bikes and cosplay attires to get smoked by 60+ years old dudes on 40 years old bikes

As a casual rider you'll be the bottleneck for years before your gear matters even the slightest

There’s also a saying in bike communities, along the lines of, it doesn’t get easier you’ll only ride faster. Riding a heavy bike with no aerodynamics will lead to building strength faster. While it can be a bit frustrating if you’re new and riding in a group, joining more beginner friendly groups and upgrading the bike later is much better overall.

It is however really important to get the posture and pedaling technique right. Way too many people in expensive gear do push-only instead of a push-pull. That’s like biking 101. It’s much better to get that smooth pedaling and core support. It’ll prevent injuries and fatigue.

> push-only instead of a push-pull

My body never got this until using fixed gear. The whole circle is important.

I've been circling the fountain pen reddit for a little while now and it's a similar thing. They spend thousands on pens, import ink from Italy, buy fancy paper, but their handwriting looks like a doctor's scrawl.

I almost went down that route! I settled for a $5 Platinum Preppy instead for a few years and picked up a Procyon recently. Don't think I'd spend anything more than that though. I tested out some $250-500 pens and didn't notice a difference but from Preppy -> Procyon is huge with how much smoother the Procyon is.

The bike subreddits are super painful. Mainly full of "Freds"

IMO there is not actually a ton of what you talk about. If anything, it's the opposite, a ton of really inexperienced folks posting about their first 20 mile ride. Note that this isn't a bad thing, just that serious cyclists aren't really hanging out there.

Calling a kit cosplay attire is silly though. There are huge benefits to a bib and a jersey.

I'm not wearing spandex because I need to be the fastest guy. I'm wearing it because it has a chamois, convenient pockets, and is a bit more aero (which means that days with a killer headwind are slightly less bad)

> As a casual rider you'll be the bottleneck for years before your gear matters even the slightest

For absolute performance, maybe, but for enjoyment of riding the gear definitely matters. For a beginner it's important that the ride is enjoyable so they don't get discouraged and call it quits.

For relative performance against yourself, and in all honesty that's most of us really get out of it in the end, it's good to see times drop and speed increase just because you bought a better bike.

For me it was the other way around, I moved from a very aero cheap fixed gear to a boxy (but with a plentiful cassette) midlevel gravel bike. I was expecting that the gears I had extra would make me have faster times, however the fat tires and less aero profile makes me about half a minute slower for a 6km round. The power I'm pushing however, has increased, maybe because I can keep it more uniform by shifting to lower gears when I get into windier sections. Shrug.

All I want to say is that good gear is beneficial, maybe not for performance, but definitely for enjoyment of a ride. And at the beginning that's pretty important for someone to build a habit out of riding.

I'm not here to advocate for expensive equipment but my cross country hardtail MTB (even with the wide tires on the roads, non-carbon) feels like half the effort to pedal than my old crummy commuter trekking bike with narrower tires, so I guess your 600€ bike might already have one of the biggest optimizations packed in ;)

That’s absolutely fine. This article is aimed at people who race bikes for fun and for a living.

The thing is that expensive isnt always better - those "cheap" Schwabe tires are actually superior than most specifically because of the way they are designed - not because they are cheap or expensive (touring style tires). You could also buy more expensive touring tires and they would be better than those cheap ones - but expensive tiny skinny tires would not (nor would big expensive nobby tires). As someone who did a lot of different bike riding and has built many bikes there are also many benefits to going pricier other than just being a wannabe racer - but in the end it is more about choosing the right style of component for the job vs just buying what is priciest or trendy.

Lots of biking? My commute alone: ~10 000km. A 600€ was crap twenty years ago. Contributions are great when the person making them has something to back them up.

If you want an astonishgly well put together deep dive on gravel and bikepacking aerodynamics, check out: https://www.cyclingabout.com/fascinating-aerodynamics-bikepa...

I cannot recommend him, his videos or articles enough. He lives on the bike, literally, and he applies an unrivaled dedication and passion to thinking and writing about this stuff while on the road. He has tests, science and real world experience to back him up too.

This is a great overview of the current state of aerodynamics in cycling. I especially loved the comparisons to what's legal in road cycling and to what the current state of the art is in MotoGP.

Also, MotoGP is absolutely worth a deeper look for anyone who found this article interesting. They've recently started taking aerodynamics to another level with front and rear winglets in a way that wasn't done before.

Bicycle Quarterly (magazine by the same folks) is a great read, always such a joy when it arrives in the mail!

https://www.bikequarterly.com/

"Some readers have suggested that the boxy shape of the bag could be improved. However, since the bag sits between the handlebars, a rounded shape was actually less aero when we tested it in the wind tunnel."

I would not have guessed that. Could a more efficient shape be made?

Yeah, the round shape is actually not very good. But it's the traditional one, from bicycle frames being welded steel tubes. The circle is still as wide as a square would be, and additionally it creates lots of turbulence. An aero frame is much more tear-shaped.

The boxy shape would likely still be less aero in isolation, but certain parts that in its slipstream might be so un-aerodynamic that the see less drag through more turbulent air than through clean air, and the boxy one provides more turbulence. Or it's the reverse, total drag benefits from the boxy rear and the rounded one was round on the rear as well (or not round at all, just some knotty wrap that approximates "round" very roughly, contrasting with a clean box)

The round-bottom shape that sits under clip-on aero bars is very good.

https://cyclite.cc/en/products/handle-bar-aero-bag-01

https://torstenfrank.wordpress.com/2021/12/07/aerodynamik-vo...

> The biggest part of a bike’s wind resistance is caused by the rider. Unfortunately, there isn’t much you can do with respect to the airflow around bike and rider

There's lots of things you can do - apart from losing a lot of weight, clothing and helmet design is probably the simplest, there's some good references to things that can be done here: https://link.springer.com/article/10.1007/s12283-017-0234-1#...

>I don’t always use the aero tuck. I find that it’s not very comfortable for more than a few minutes at a time

I cycle on a time trial bike (not on gravel) - which has a higher saddle and longer frame so back and arms can get straight and horizontal. It took a lot of effort to get comfortable physically and mentally in that position (you hands feel a very long way from the brakes) and you do loose quite a bit of control in that position, but I don't see why a slightly higher saddle and arms horizontal but wider with hands at the edge handlebars in line with legs wouldn't be possible.

The most aero time trial like position need training, especially the muscles in the neck area. Even in the pro racing world some racers do not train enough in that position and lose precious time in time trial because they are unable to keep it straight looking at the road constantly and move the head up and down constantly. The helmets manufacturers actually accounted for that and moved to time trial helmets with a much smaller tail as it spent to much pointing in the air.

Gravel has washboards, pot holes, trenches, lips, fallen trees, overhanging trees/brush, large rocks. I'm thinking a lot about downhill riding too with respect to your comment. For a downhill section on gravel, for a 8% grade descent - safety is perhaps the biggest limiting factor. In some gravel races, it is really debatable whether a hardtail or a gravel bike is better. That is all to say is that stability demands can greatly vary from one section to another on a gravel/mountain race course.

Back in the day I found some vintage "aero" bars that were designed to bolt on to any bicycle made before larger diameter drop bars became the norm. I did not want them, however, specifically for the "aero tuck" - I wanted them to give me more hand positions for long term comfort. While I eventually got rid of them because they took too much space on the flats of the bars due to the way they clamped I always wondered if we could design something like an aero bar but specifically for comfort. It could bolt on to the stem or in a way that still allowed multiple hand positions on the flats. The elbow pads were also a very nice way to get some lower back stretches in and I even ended up mounting a small cyclocross brake at the end of one of the aero handles so I could comfortable adjust speed (rear brake only - front brake in this position might be suicide) while going downhill and tucked. Or hell - maybe even something that had a small fold mechanism so that you could fold away the forearm / elbow pads when not in use!

The aerodynamics of upright bikes compared to recumbents remind me very much of stock car racing compared to f1. Where one is actively pushing forward in terms of speed and performance and the other is stuck with one type because of how it "should" conform to previous ideas of what a bike looks like.

I bought a cool book yesterday which is all about gravel trails in the UK. I had never heard the term gravel bike until reading it.

Silly question but can I do these trails on my full suspension mountain bike, or will I be mercilessly mocked and possibly chased out of town?

I already have a mountain bike and a road bike so not keen to add a third!

You will certainly not be. At least in the US, mountain bikes for trails are still the norm.

A mountain bike is fine on a gravel trail, if you can lock the shocks

> ... can I do these trails on my full suspension mountain bike...?

Yes. It will be a bit more work on the pedalling front vs a dedicated gravel bike, but I doubt you will encounter any bike snobbery. I have gravel trails near where I live, and you see all kinds of bikes tackling them.

If anything, you might be thankful of a full suspension mountain bike on some of our "gravel" trails in the UK. There's such a wide range from US-style back county roads all the way to bridleways with baby-head sized rocks that you probably wouldn't want to be riding on something typically sold as a gravel bike.

Yes, this. There's actually not that much US-style "gravel" in England and Wales: basically a few Forestry Commission tracks in mid-Wales, Northumberland and places like that. Elsewhere it's single-track bridleways that dominate. Routes like King Alfred's Way, the Pennine Bridleway, the Great North Trail and West Kernow Way are sometimes marketed as gravel routes but they're probably more MTB than anything.

I spent a month in the UK and was glad to have brought my CX bike instead of my road bike. Several of the routes (in Kent) that I had thought were going to be road routes suddenly turned into paths that we would classify as gravel here in the states. It was wonderful! So little traffic and not one F350.

"gravel" is more of a mindset. Yeah, granted, it's been taken over by most marketing departments trying to push people into buying new gear, but ultimately, it's about being able to ride both paved roads and whatever tracks are there in the outdoors nearby.

There's always the debate / meme of "are gravel bikes just 1990's hardtail mountain bikes with drop bars?" and ... the jury's still out on that one ;-)

AFAIK a full suspension is an overkill, but if it's what You got, go for it. You'll just be a bit slower.

If You're looking for some testing, perhaps try to just get yourself a new pair of gravel tyres that fit Your wheels. That's by far the biggest source of resistance. If it's fun, pick up from there. There are plenty of videos on youtube on how to hack into a gravel bike a cheap old frame (either hardtail MTB, or some CX / touring frames). Doesn't have to more than 100-200EUR / USD in the end.

It will certainly be more of an effort with the fully, but I don't see anything wrong there. I'm not even sure we have a lot of so-called gravel trails here (not the UK) but the norm is more: people ride on MTBs and sometimes there's a rider on a gravel bike or cyclocross.

> I already have a mountain bike and a road bike so not keen to add a third!

Why would you say that? :)

Any bike you ride on gravel is a gravel bike. All my bikes have been on gravel so they are all gravel bikes.

Yes! First, if you haven't spent much time on gravel, you will be more confident and sure-footed on the MTB. Second, you will have a much more comfortable ride. As others have said, it will be a bit more effort, but the improved confidence will probably do more for your overall speed than a skinny tire.

I would however lock out the rear suspension, and probably the front too. The high volume tires at the right pressure will likely provide all the suspension you need for gravel and your pedaling will be more efficient.

As far as being mercilessly mocked, that reminds me of an old adage. We spend our youth worrying about what other people think. In middle age we decide we don't care what other people think. As we get older, we finally realize no one was thinking about us.

The article mentions the upper back fairing of a motoGP racer but then blows off the idea for a cyclist because they might get too hot? I've always wondered why road cyclists don't ditch their frame mounted (and drag inducing) water bottles for a camelback. The original camelback was slim and I can't imagine it added any drag seeing as it sits on the back of the cyclist. Plus it has the advantage of allowing the cyclist to maintain a better cylcing position without having to reach down for a bottle.

But then again if roadies were really all that concerned about aero and efficiency they'd switch to recumbent bikes...

In pro cycling it's actually forbidden to have aero fairings on your bike. During the Armstrong years there has been a controversy about the placement of his radio on his back during time trials that would incur fairing.

> The biggest part of a bike’s wind resistance is caused by the rider. Unfortunately, there isn’t much you can do with respect to the airflow around bike and rider.

I have an idea about that, and I would like to explore it. Not having a mechanical engineering background, what do you think would be the best way to build a prototype, patent it, etc? Is there any engineering firm that would provide such service, let's say in Europe?

I ride a Trek Domane 5 AL which allows spacing for a 48mm tire ( odd for a roadie ) - so I put a 48mm gravel tire on it and started riding it on light gravel. Works very very well. Carbon would be even better but Id still be waiting on it to arrive from the factory alas the aluminum version will have to do. The best bike in the world is the one you have in the garage to ride today.

Related, this fascinating video, which covers different bag positions, clothings etc.: https://www.youtube.com/watch?v=Ue_Tz7e0DmE

I'd also suggest this Francis Cade video1[1] where they tested various bike packing bags in a wind tunnel.

Bar bags of any size or shape are really slow.

A much better solution is something like a Tailfin aeropack[2].

1. https://www.youtube.com/watch?v=WcXh_oqs_Bs

2. https://www.tailfin.cc/

wondering if i should switch handlebars to narrower one. so currently i have 56 frame with 42 handlebars - thats "factory" setup. i noticed that also 54 frame has this handlebars, only 52 size frame comes with 40. anyone has any experiences how it will affect bike handling? i noticed that there is a trend rising to go with narrower handlebars on gravel bikes

I personally go with the widest handlebars I can. You might gain some aero from skinny ones which would be worth it if you are racing at a high level but you will lose a significant amount of comfort. Wider bars allow more hand positions and are significantly more comfortable for me especially on long rides. Being able to really get a wide grip occasionally feels great on the shoulders. And on top of that you feel much, much more secure with a nice wide grip on difficult terrain like shitty pothole laden roads.

They milk the topic. This could have been 2 pages at most: Aero bars are dorky, doubly on gravel, but they will make the most difference. Heck, clip a fairing to those aero bars. But nobody uses them because you look like a dork. If you can't get over looking like a dork, and you are susceptible to bike marketing <cough>GCN</cough> you'll spend thousands on an aero frame. And then you'll put a hipster handlebar bag on it.

I’m sorry but Jan Heine has unscientific methods and his products are of questionable reliability. You can drop 200usd on his tyres. It’s like hifi nerdy but for rubber.

I agree the tyres are expensive, but their findings on tyre width and pressure are largely bourne out by more controlled tests.

In addition, their rolling distance tests include one factor which most standardised rigs didn’t: the losses from hysteresis when uneven surfaces have to lift/return your mass over a bump. I think soft wide tyres would be even more advantageous than most people realise once real losses on real roads are factored in, and compared at speeds most cyclists go at (i.e most people don’t average 30kph). In fact, even using average trip speeds as the comparator would be daft because that would include downhill sections where riders are actually braking, or don’t really care about rolling resistance because the difference between 50 and 55kph downhill makes no practical difference.

The tire width definitely has a break even point where wider tires are significantly less efficient than narrower ones unless you run them at unsafe pressures. More volume in the tire means that at the same pressure, there is more deflection, and deflection hysteresis in the tread, notably the rebounding of the tread behind the contact patch is what causes the rolling resistance in the first place.

RH 48mm tires at 25psi are pretty damn good on a single. Likewise my tandem uses 44's at 45psi (front, heavy captain) and the rear 53mm at 40 (light stoker).

Totally agree. I do think that people underestimate the width of that point tho. For most people who are not racing the suspension benefits probably outweighs the minimal aero loss, but it’s really hard to measure. I have been on fast group rides on 48mm slicks and although I get funny looks (and am not going to win many races because I’m old and lazy) I genuinely L find it easier to keep up than on 28mm tyres i had previously. Part of that is confidence maneuvering at speed on fairly crappy roads though.

Where are the supposed alternative people with scientific methods?

I don't know but I'm also not trying to market very expensive tyres.

Two of the best people who are not selling anything are Tom Anhalt (http://bikeblather.blogspot.com/) and Robert Chung. They both post a lot in various forums like Weight Weenies (which is more about rolling resistance and aerodynamics now that we know that they are more important) and Slowtwitch (more triathlon focused but has a lot about general bike tech).

Josh Poertner from Silca is also good but has things to sell.

Of course what everyone is saying above is right -- fitness and rider weight matters the most. But it is fun to look at this stuff especially once you have achieved some level of fitness.

bicyclerollingresistance.com

These in-depth scientific studies always seem to neglect the weight and aerodynamics of the RIDER. That is surely the biggest factor when it comes to speed and efficiency.

Harder to spend money to improve the rider. Fancy clothing, I guess.

Weight reduction is much cheaper on the rider than the bike in many cases though.

A skinsuit or roadsuit will definitely make you faster on the bike. It's pretty easy to measure the effect with a power meter.

Weirdly "aero socks" are both a thing and make a big difference to the point that they are heavily regulated by the UCI.

Any cylindrical part of the bike or rider is going to perform badly so if you can encourage the airflow to stay attached around it you reduce the amount of effort required to move you forward, hence aero clothing being a big deal.

If you're a serious cyclist then it's pretty easy to spend money on good quality clothing.

Always made me wonder if taking the swimmers route instead would provide all the same benefits without the cost and look. Shave your whole upper body and go shirtless and you would be pretty damn aero no? Would a skinsuit really improve upon that?

In addition after switching to a Brooks saddle (I tried literally 10s of saddles using the "saddle swap" forum feature on some forums) I now no longer ever want to use padded bike shorts again. Of all the short types the simple padded chamois was my favorite (simple foam - no gel or any other BS) and now I just prefer wearing a pair of synthetic lightweight boxer briefs (no fly) that were designed for hiking originally. There is no padding at all and from day one the brooks was extremely comfortable. It only got more comfortable with time and applies all pressure directly to my sit bones. Every other saddle + padded short (even ones that mostly were on my sit bones) ended up forcing padding into the areas between my sit bones and outside them as my weight compressed the padding. I havent tried their new non leather seats but they seem to operate by a similar tension (a tensioned pliable surface vs a hard plastic shape with padding on top) which results in your weight creating additional space below the sit bones vs filling it with padding.

It's actually been tested and modern fabrics are better than bare skin for drag.

In Michael Huchinson's Faster[1] it mentions that they tested a rider naked in a wind tunnel to find out!

If you look at a modern TT skinsuit you can see that they try to cover as much of the arms and legs as possible. They usually stop above the elbows and knees because it's hard to cover the joints without wrinkles.

Likewise, socks are now as long as permissible (without breaking the UCI sock rules!), which I think is about halfway up the calf. It would be faster to cover all the way up to the knee joint.

It all sounds silly if you don't race but if you've put some effort into getting fit then after awhile it's hard to gain even 5 or 10 more watts. If you can reduce your drag by more than that just by wearing a better pair of socks... well why would you?

BTW I have a Brookes on my commuter Brompton too. :D

1. http://www.michaelhutchinson.co.uk/faster.html

The rider is a much bigger factor, of course. But that’s not the problem being addressed here. You’re not suggesting the bike should not be optimized are you?

It makes no sense to optimize the bike in isolation. There is complex airflow interaction between the bike and rider. There are changes that aerodynamicists could do to reduce bike drag that would actually increase drag on the complete bike plus rider system.

The problem is that there are so many variables with riders. For example, just a slight change in head position can increase drag more than any improvement in frame tube shape could save.

For sure, and the bike industry tricks huge numbers of slow people into vastly overspending on their bikes with no real benefit.

They basically never test these aero bike gadgets on a rider.

Aero helmets and clothes are probably the only ones that get tested on riders in a valid way.

Just be careful not to use "illegal" aero socks.

https://www.cyclingweekly.com/news/racing/check-illegal-sock...

It's always funny with people having paid $10k extra to save a kilogram on their bike, and then show up on the Sunday group ride with a beer belly. But I think these articles and study are mostly written for / paid by professionals, and they don't have that much more weight to lose.

But reading "The secret race" by Hamilton (one of Armstrong's team mates), they do focus obsessively on it. They would often ride for hours, then take sleeping medication and go to bed without eating.

They are climbing mountains though. In a flat area this advantage nearly disappears. I have that typical cyclist underweight build and it barely helps me on gravel rides, really only when there's a direct headwind. And it's balanced by how much more I get pushed around by crosswinds.

It's definitely very significant for european-style touring races, but people overstate it for even high-level amateur rides especially in flatter areas. Which is most gravel riding.

> It's always funny with people having paid $10k extra to save a kilogram on their bike, and then show up on the Sunday group ride with a beer belly.

Ah, the smell of fresh gatekeeping in the morning. You don't know what road these people are on, just their current state. For all you know, they've already dropped dozens of pounds and are happy with their own improvements. Never look down on a fat person on a bike.

I didn't gatekeep or look down on anyone, those I'm talking about is me and my friends. It's just a funny jab at ourselves, spending way too much money and effort on things that ultimately wont matter. At least we have fun doing it :)

I'm a cycle advocate and spend hours a week fighting for infrastructure etc where I live, that I hope helps all kinds of cyclists.

When framed that way, it seems odd, but is it so strange that someone with means spends $10k on their hobby? That's really what it comes down to, more so than the weight-savings. If you like riding bikes, and have the money to spend on it, why not spend $10k on a fancy bike?

This article addresses the rider in detail.

You should read the article, rider positionning and clothing is mentionned.

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