New front gearbox design for bicycle | Hacker News Reader

New front gearbox design for bicycle

efneo.com

38 pointsajuc23 comments

More info: http://www.bikeradar.com/news/article/crank-based-gearbox-in-development-35979/

http://www.efneo.com/how-efneo-gearbox-works/

As a former bicycle mechanic and salesman, and someone who is still very tuned into the industry, I'd give this a zero percent chance of actually being successful.

There are three big issues with this design. First of all, you're going to be looking at a seriously increased Q factor trying to fit three different speeds into that gearbox (as opposed to Truvativ's two). The Q factor is the amount of distance between your feet. If you lie down on your back and make a pedaling motion, the natural positioning of your feet is one banana apart. Bikes, to have sufficient stiffness in the bottom bracket region, space your feet two banana's apart or more. Graeme Obree (https://en.wikipedia.org/wiki/Graeme_Obree) figured that out, and when he designed Old Faithful he added a very narrow Q factor, which was a big piece of his success. A huge benefit of carbon fiber is its ability to add stiffness in the BB area by overbuilding without increasing Q factor (or weight all that much), hence the BB30 standard. Truvativ's two-speed front crank is already very widely spaced, and trying to fit more in is going to cause problems. Remember, to balance out the pedal stroke, you have to compensate on the left pedal (I see this is designed to work with existing tech, but it'll feel strange unless you get a longer left pedal spindle), so every increase in distance on the right side is doubled.

Secondly, no part on the bike gets worn out quite like bottom brackets (not including "wear" parts like chains, cassettes/freewheels, tires, etc.). Powerful riders (and not necessarily racers, I know plenty of everyday commuters who fit this bill) tear BB's to shreds. I am a racer, but I'm also a lightly built climber, and I tear through them pretty regularly. Putting a gear box in the BB shell is going to subject it to a hell of a lot of torque, and it'll be difficult for it to stay dialed in and functional with the power output of many riders. The extra mass could also make it uncomfortable to stand up and power out of the saddle. Trek, Pinarello, and a few other companies already reinforce the non-drive side of some of their bikes to even out the extra weight from the chainrings and front derailleur. All the extra mass from a gear box will expound this.

And lastly, internally geared systems are a bitch to maintain, and it's one of the reasons why you will be hard pressed to find a shop which will overhaul your vintage three-speed hub. The newer internally geared systems (like Shimano Alfine and Nexus) are a lot easier to work on, but Shimano spent decades perfecting that stuff. This system is not going to be easy to work on to start, and good shop owners don't sell products their mechanics can't fix easily. It's just not a good proposition.

All in all, a cool idea, but to me far too many issues for it to ever be accepted. As that bikeradar article puts it, no need to reinvent the wheel. Internal hubs and derailleurs (the latter especially) get the job done quite well.

Came here to say this. Internally-geared rear hubs are great for certain mountain bikes, where derailleurs just won't work because there is too much mud. But for everyone else, a well-adjusted derailleur system will be fine. (Yes, you have to pedal forward to change gears. If you're stopped at a light, press the front brake and move the pedals forward. Or remember to downshift as you're braking.)

I've thrown a chain twice in recent memory: once when I was climbing on a chain where I disregarded the rule against breaking the chain without replacing the pin with a master pin (that you break off after driving in), and once when I was trying a new kind of lube on the chain (that worked more like glue than lube). A well-maintained derailleur system is very light and very efficient, and with a bit of practice, easy to use.

Mud always comes up in these discussions but isn't a real problem. You can get mud, water, sand, branches, snow, grass, gravel or entire bushes into your gears and hardly notice it. Sometimes it feels like the whole forest just wants to go into your gears but in some magical way it always falls out again. The more i think about it the more amazing i think it is, the amount of punishment the powertrain takes is quite remarkable and even though the components are so small and precise they don't take much damage.

The only real problem with derailleurs in the forest is when they get hit by a rock, a think branch or the ground. Anything else that doesn't actually bend the derailleur is a non issue. In very very rare occasions something might jam the chain but no changes in the gear are going to fix that. And of course the mud will slowly wear and tear things down by grinding but that's not an issue of the actual gear but more of the cogs and chain.

Ah yes, the derailleur thing sounds like the real issue that internal gearing aims to fix.

My reading of the article suggests that it's targeting more casual riders that bop around town, but maybe live in a hilly place, haul kids, etc, and could use some extra gearing.

All your criticisms may be true, but seem to be more about the needs of "enthusiast" / "serious" riders (a category which includes many bike commuters in the U.S., but not so much in other countries).

So despite the issues you mention, there may very well be a place for this tech—and the "non-serious" market is much larger (especially outside the U.S.)...

The cost of this system worries me. The "casual rider" around the world rides very inexpensive bikes. For instance, it's rare to see someone in Japan commute with a bike that's over $150. Low end Shimano components are pretty inexpensive due to their massive volumes. I'm concerned of the possibility that this product is being developed without having rigorously tested for product market fit.

> It's rare to see someone in Japan commute with a bike that's over $150.

Lots of people have cheap bikes, but there's also a big "mid-market" (~$500) for Japanese casual bikes.

I think a robust and trouble-free multi-gear front could be a great alternative for recently popular electric bikes (e.g. on those small-wheel bikes with kid seats)... even if it adds weight and cost, it's surely much less weight and cost (and hassle) than an electric motor and battery...

In france there are pools of bikes to rent in big cities. There are many pools in many places so that you cant pick a bike in one place and leave it at another. These bikes could benefit from such gear system. It has to be extreamly robust to common usage with user not carring about the bike or hardly now how to bike. The bikes are cheap and I think the first half hour is free. Howerver it is a profitable business. So there might be use cases where this product could be a good fit. Its weight seems however to be a bit excessive. Its called vélib.

OK, but you don't actually know the Q-factor of this design, nor how durable it actually is. You're guessing based on not a lot of information.

Although I am also skeptical of new mechanical designs on something as evolved as bicycles, it seems like a good idea and one worth pursuing. Why declare it a failure before the first review!

You can't tell me one and even larger one of these isn't going to cause some Q factor issues. This (the Truvativ) is designed for gravity riders though, where pure pedaling efficiency and fluidity is not at value. Same goes for durability not being as much of an issue. This needs to take rock blows, not miles of wear. I read this product as for commuters and people who put in a lot of miles around town:

http://mtobikes.com/wp-content/truvativ-hammerschmidt-detail...

And yes, the durability is entirely speculative, but, especially coming from a new company (as opposed to HammerSchmidt, which was 100 or so years old when SRAM, of which Truvativ is a brand bought them), I'd have serious doubts they'll put a top quality product out at the start.

One more thing: Weight. Inventor states the internal front gearbox is..."Light and compact – much less than 1kg weight and 20mm width."

A front derailleur typically weigh 50-100grams.

Another article about that system: http://www.bikeradar.com/news/article/crank-based-gearbox-in...

What's the target market for this product? (Another way to ask this question would be, which subforum at bikeforums would be interested in this?[1]) I fit into the commuting, road biking, touring, and classic bikes sections, and want no part of this product.

As a 30 mile a day bike commuter, I want relatively few failure points as possible in my machine since I don't want my shifters to go bonkers on me as I'm going home at 9pm in sub 40 degrees weather (I'm going to be replacing my STI shifters with barend shifters soon). If I were a city commuter, I'd probably going for a simple fixed gear or similar set up, and certainly don't want a bike that would be a magnet for thieves. As either type of commuter, this component is out of my price range.

As a road race style cyclist, my front derailer is of high enough quality that I have literally zero problems shifting from small ring to big ring or vice versa. I never have a situation where I need to shift the front gear while stationary, since any adjustment I need will be small enough to be covered by moving up or down in the cassette. Thus the "shift front gear while stationary" benefit is a moot point for me. As for weight, the Shimano Dura Ace components that you'd go up against don't add up to 1kg when looking at crankset + BB cup + front derailer [2], so I don't really see a weight advantage either.

If I'm on a tour, there is no way I want a complex gear system that can break down and leave me stranded. I'm going to go for a barend or downtube shifter setup.

As a classic bike aficionado, I have negative interest in this product.

That being said, jrockway has a good point that this may come in handy for mountain biking because of the mud issue, or cyclocross for similar reasons. Maybe these segments could make sense for this product?

[1] http://www.bikeforums.net/forum.php [2] http://www.totalcycling.com/component-weights.html

Dura ace is a competitor to this? When it's all said and done, it's going to be too expensive for most commuters and maybe that makes it like "durachi" but if it has any market it will be for the suburban super commuter buyers.

Put a belt pully on it and if its reliable maybe you'll see it on some of the $1500+ super commuter bikes. The nexus, roloff and alfine are all remarkably reliable, just pricy.. The appeal isn't weight, it's durable purpose built commuter stuff. Maybe some downhill honks will like it but I've seen a whole lot of those guys just riding single speeds any more

Would people from outside the bike industry please stop trying to reinvent the wheel?

There's a much better internal gearbox already available. The three-speed planetary gearhub has been in production since 1936 and continues to work brilliantly, essentially unchanged since. It's cheap, light, phenomenally reliable and highly efficient. They're ubiquitous on European utility bicycles, because they will run for years without any sort of maintenance or adjustment. You can have one in a variety of ratios, with a coaster brake, roller brake or disc mounts, or even with a standard cassette spline, allowing you to use any derailleur system in addition to the internal gearhub. At the expense of some efficiency and durability you can have eight speeds built into your rear hub; At the expense of about €1000 you can have a 14-speed Rohloff, as favoured by most round-the-world cyclists.

People from non-cycling cultures seem convinced that the key impediment to widespread cycling is technical and tend to jump on any supposed "innovation". The truth is that cycling development is primarily a social issue and requires no new bicycle technologies or special infrastructure. It is for this reason that the promotion of cycling is both much easier and much harder than most believe.

This is a gimmick. It's gimmick engineering, really.

I'm a commuter by bike. I want something that can still work after driving it through winter without constant maintenance. But the only thing coming out of that industry is gimmicks. It's a market designed around either enthusiasts that spend every second refining their subtle creations, never getting to ride them, or parents who need a cheap bike for their kids to demolish and consume.

> This is a gimmick. It's gimmick engineering, really.

Is it a gimmick (I dunno)? Their apparent goal, a more robust and less finicky alternative to front-derailleurs, seems pretty much in tune with what you want...

> It's a market designed around either enthusiasts...or parents...

Look outside the U.S. for very different approaches, e.g. Japan, where bikes are ridden by everybody (bike mode-share is an order of magnitude greater than even bike-friendly cities in the U.S., and far more evenly distributed amongst sub-populations), and generally not fetishized (there's an enthusiast market, but it's very small by comparison).

I agree that the U.S. market historically resembles your description, but that's started to change in recent years as the overwhelming obsession with automobiles has cooled, and we start to enter the "post auto age" (very slowly in the U.S. of course!). American biking culture is still very influenced by older patterns, but this is changing too.

A significant aspect of the Japanese market is the prevalence of $1,200 electric bicycles, which now appears to be at around 30% of bikes seen around in Tokyo. Automatic gear shifters on standard bikes are fairly common too. Also pertinent is the fact that Japanese tend not to repair their own bicycles - not even a puncture. Rear brakes are typically not user serviceable anyway. So I suggest they should try to ride the EB wave in Asia to market this system at first.

> A significant aspect of the Japanese market is the prevalence of $1,200 electric bicycles, which now appears to be at around 30% of bikes seen around in Tokyo

Electric bikes are a somewhat popular niche lately, but there's absolutely no chance they account for anywhere even near 30% of the bikes in use in Tokyo. The number of bikes, and biking population, in/around Tokyo is immense, and the vast majority of them are not electric (nor new, nor particularly fancy). Even amongst the recently popular small-wheel-two-kid-seat bikes, most don't seem to be electric.

But you're absolutely right that the Japanese bike market would be a good one to target; it's very big, more upscale than many other countries, and oriented around practicality.

Perhaps my observation is skewed by the fact that I see so many mothers dropping kids at the houikuen (nursery) are using them. Also at my suburban station bike park, I estimate 30% are eb. If you count bikes in use, as I do, rather than those static outside a mansion, you get into the 30% ballpark in my neighbourhood. I am not sure whether this new gear tech suits EB, but it seems it might be good for them to ride the eb trend , which is large and growing.

What about shaft-driven cycles? I've never tried on, but wanted to, as they seem like they would require a lot less maintenance. And I'd get less grease on me.

Could see it used if you ran it to a fixed hub in the back. You could have multiple rations while keeping cleaner lines and all. But you would still have shift hardware....

Definitely an enthusiast product looking for a problem.

This reminded me of the Rohloff Speedhub (http://en.wikipedia.org/wiki/Rohloff_Speedhub).

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