Hacker News Reader

Comment by derekp7 | Hacker News Reader

But does the sub 20 lb bike really gain you a lot? For reference, I weight 220 lbs -- so the difference between and 18 lb and a 30 lb bike really doesn't seem like a lot. I guess what I'm asking, does losing 5 lbs on a bike equal losing 5 lbs on the rider? Logically this would seem the case.

But there is probably one other factor to consider -- the lighter bike is more expensive, therefore probably has better components (chain/shifters/bearings/tires/gears), which makes it feel smoother. And if it feels better, you will get the perception of higher speed or less effort.

View on HN

It's mostly about the rider, but when you get to the elite guys, every little bit counts. You and I probably have 5 pounds to lose; they don't:

http://c.files.bbci.co.uk/16E6F/production/_84270839_froome....

The main reason I prefer a lighter bike is for when I need to carry it up some stairs or something like that. For most everyday riding I don't think weight matters much.

I feel the same about carrying the bikes up stairs :-)

However there is a noticeable difference in riding as well, unless you ride only on short distances.

You can simulate the difference on the same bicycle so the comparison is not tainted by different tires and mechanical components. You can add 5 kg (or 10 pounds) here and there or even in a backpack (but it will harm your performance in other ways). Maybe don't put weight on the steering/front wheel because that will make for a difficult handling. You can use water, so you can release it at any time and feel the difference.

You'll notice that with the extra weight you accelerate less and climb worse. All sort of disadvantages derive from that. If you do 100 km and you have a choice, you'll go for the lighter bicycle. Unfortunately that means a lighter purse as well, maybe much lighter.

Lighter bikes don't make you faster in steady speed riding on a perfectly flat surface. The hour record bikes are optimized for everything but weight.

But we are very bad at judging absolute speed without technical assistance, while being quite sensitive to acceleration. Therefore, a slight increase in acceleration for a given effort (or decrease in effort for a desired acceleration) is very noticeable, while an increase in absolute speed would not. So a lighter bike will feel noticeably faster (even though it isn't), while different aerodynamics (e.g. "faster" clothes that give a lot more improvement in absolute speed than a weight difference, even for weak riders) might give a clear advantage on the clock, but you won't be able to notice it while riding.

Light bikes just feel fast, very much so actually. It's a powerful illusion that only gets stronger because it is supported by those few specific situations (stop and go, races with tight corners, all that climbing road cyclists love) where the weight also matters objectively.

I've only ridden super-light bikes rarely. Still, among the ones that I've ridden, lighter bikes seem more responsive and fun to ride. Is it a big deal? Probably not. Will it win me a race? No, that would still require a much better motor.

And like you say, better components can make a difference, within reason.

For those of us who ride road bikes, yes sub 20lb makes a big difference. My Fiancee's road bike with Sora components is just under 19lbs and that's pretty basic as far as a road bike goes.

It gets a lot more expensive once you go sub 14lbs, and very very expensive sub 10.5lbs or so. (20k+)

Sort of.

When I was towing an empty 20+ lb trailer, and the bike +rider was in the 210lb range (so, 10% of the mass) I was about 10% slower than sans-trailer. Towing a trailer + 25lb kid was about another 10%.

A lighter bike _may_ feel different, but whether it's weight or something else, or even placebo is up for discussion. It's hard to tell frame weights. 20 years ago, I ran some blind testing where we put weighted waterbottles in a frame, one with lead, one with glass beads, and one empty. 5 trials, A/B, which one was heavier. IIRC, adding 5 lbs of lead was noticable to almost everyone, but the difference between 2.5 and 5 lbs was only noticeable to the frame builder.

It's interesting.

Cycling is unlike any human powered sport except iceskating in that aerodynamics play a huge role. That means packs are the default state of play, except in a few limited circumstances.

One of those cases is climbing, where speeds can be low enough that a few pounds makes a big difference.

Reply on news.ycombinator.com