tcrown

I've been thinking that everyone on this board is crazy for being so obsessed with the weight of the bike....that is, until i bought a halogen light and can definitely "feel" the added weight when riding. Can someone help me out with the physics here? You've got a 180 lb guy on a ~ 20 lb bike. adding a 1 lb weight is 1/2 of a percent of additional weight. how does that have such an effect? as an aside, i've already lost 2 pounds since starting to bike a few weeks ago, so technically i am lighter than when i started even with the light.

the answer may be that the perceived additional drag on my speed is purely psychological.

damocles1

It doesn't...

Ride harder...

Az B

It weighs on your psyche and that's what really slows you down. Sure, a heavy bike will climb a little more slowly, but a depressed person simply can't rise above any elevation.

So it's definitely psychological.

Az

rschulze

I am one of the weight weeny types that has a sub 15lb bike. It helps climbing, that's it. If you have a 18lb bike and you lose three pounds, we're even. It actually helps descending having more weight, the heavier guys can fly down a freaking hill.

Ever notice TT bikes are always heavier than their road cousins. They bank on being more aero and making their riders more areo too. They are not concerned with weight, a disc rear wheel weighs almost as much as both of my wheels.

Find a bike you like, that's comfortable, that you will ride ..... don't get obsessed with the weight unless you have lost as much weight as you want and climb a LOT of hills and the extra weight will make such a difference that you're willing to pay a ton more for your bike.

The best thing about a sub 15lb bike.....bragging rights. Beyond that, it's fairly limited.

redirekib

Remember...the mass of the ass is equal to the angle of the dangle.

mwrobe1

It has a nominal effect in climbing and acceleration.

All else is:
1 part subjective psychological perceptions
10 parts really LAME entries to the "have-to have the lightest bike evar" penis measuring contest.

ratebeer

1. Run a mile for time
2. Run a mile for time with a one-pound weight in each hand
3. Any questions?

While you won't feel it on the flats, you will feel it going up hills.

wanders

I am the weight on the bike and there is about 40 lbs too much of it.

jrobe

People are obcessed with weight because it is easier and more fun to spend money on equipment that it is to do train harder.

rhennigan

All bikes are 30 lbs.

A 10 lb bike needs a 20 lb lock
A 20 lb bike needs a 10 lb lock
A 30 lb bike needs no lock

alanbikehouston

Rotating weight, especially at the outside area of the wheels, the rims and tires, has an impact on your ability to accelerate and brake.

But, total weight has a trivial impact on level roads. A 200 pound cyclist trades his 22 pound bike for a 15 pound bike. With equal wheels and tires, going down a level road at 20 mph with a total weight of 222 pounds versus 215 pounds...over an hour's ride, there might be just several seconds of difference related to weight. Climbing a mountain, the difference in an hour's climb becomes more significant...important only if you are a pro, where seconds count.

But, weight does give roadies something to obsess about and brag about...roadies love to brag "Mine is smaller than yours"...and they usually are telling the truth.

Duke of Kent

I plan on showing up at U23 nats next summer with a 6.8kg bike and a 62kg me.

I don't want either element to hold me back.

Bacciagalupe

+1

Rider fitness & flexibility, position, tire tread, tire pressure all have more impact on performance than weight.

Chances are something else was going on that day -- e.g. slightly stiffer headwind, or you weren't 100% recovered from previous efforts.

There are only two times weight actually matters: 1) if you're racing at a high enough level that 30-60 seconds, over 4 hours of racing is critical, and 2) when you're carrying your bike on stairs and/or over a turnstile.

DinoShepherd

Lights are funny things. I have found that I can feel weight up high, like lights.

I remember when titanium railed saddles came along. The weight savings was only a hundred and change grams over a regular Turbo style, but it felt like 10 pounds because of where it was carried.

Bob Ross

I love all these discussions about how bike weight has no impact on performance or speed (and I'm not disagreeing; in fact, empirically I've noticed that my ~17lb bike rides no faster than my ~23lb bike) and that the only reason to want a light bike is for bragging rights or to compensate for Small Dick Syndrome blah blah blah...

Am I really the only cyclist who appreciates a light(er) bike because IT'S EASIER TO CARRY UP A FLIGHT OF STAIRS?

Seriously. I live on the 4th floor of an apartment building with a notoriously unreliable elevator. I regularly (like 3 or 4 times a week) ride across the George Washington Bridge, whose north path has a total of 165 steps over six separate staircases. Plus I store my bike hung from an 8' tall pole, which means every single time I ride I have to lift my bike over my head. (And that doesn't include the days I win the race and have to lift my bike over my head in a victory dance.)

Hells yeah I want a light bike!

Bob Ross

A-ha, see? I'm not crazy!

urbanknight

It's all psychological. I bet if we put the light on your bike somwehere without you knowing, it wouldn't slow you down. That's why I like seat bags. I am not "feeling" the weight of my tube, keys, cell phone, tools, etc.

And as said above, my bike could lose maybe 4 lb at the most, while I could stand to lose another 10, maybe 20 if it was replaced by 10-20 lb muscle.

mikeoverly

What the others said, but I'll add some observations. There are about four pounds between my heaviest and lightest road bikes. There is no doubt a climbing difference, but on my usual routes I just can't feel it, because there's nothing steep enough for long enough to highlight the difference. For the rest of any given ride I notice some negatives about the lightest bike: namely that the lighter bike (18.5#) is "busier" under me and doesn't maintain inertia as well as my heavier bikes. IOW, a rough patch of road slows me & the light rig down noticeably more than me & a heavier rig, the latter which pretty much glides over the bumps without much speed loss.

Still, it's fun to build & ride a light bike. The obsession is here to stay in this sport, but unless you're racing at a very high level and your sponsor is shelling out the bucks for your 15-pound wonders, you might think twice about paying big bucks to shave a few ounces.

forrest_m

just to throw in another $.02, while i agree with most of the comments about overall bike weight, i definately do notice the change in handling when i plonk my winter-nighttime front light onto my handlebars. i get used to it pretty quickly, but it's fair to say that weight can have an out-of-proportion effect when it is located part-way out a lever arm...

flipflop

It doesn't matter much in practice. If you average 14mph on a 20lber an insanely light bike isn't going to push you to 15mph.

Does make for a pretty decent hobby though, tinkering.

banerjek

While it is true that as a percentage, the weight and speed differentials are small, you can definitely feel the difference. Your body adjusts to the weight that you are and doesn't perform all these calculations to figure out that the differences are minor. Try carrying a couple pounds with you all day and convince yourself you don't feel different. If you are a fit 140lb person, try strapping an extra 60 lbs to you all day and compare how you get around to people who barely exercise.

When I commute (particularly in the winter), I carry a lot of gear and I'm not a weight weenie by BF standards. However, I can definitely feel the difference when I lug more clothing or stop by the store to pick up a gallon of milk.

While it is true that shaving 3 pounds off the bike will only make you marginally faster, you can still feel it -- particularly when accelerating or on extended climbs.

stapfam

Do a century on a 21lb bike and then do one on a 15lb bike. Or climb a mountain on the same- Or look at your bank balance for the opposite effect.

dur4ce

I completely agree. And I am one of those people who really enjoy buying having and using nice bicycles. Its just another part of the cycling ethos. Its not for everyone, but for those whom it is for, its really fun!

Might as well get dropped on a nice bike than a beater!

-Steve

Duke of Kent

A 15lb bike can be had for less than $3k, which, in the grand scheme of things, is not a huge sum compared to what people are spending these days.

littledjahn

If the light is on your handlebars, it's probably making your bike handle a little differenltly. I'll bet that's what you're feeling.