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How important is weight?(20 posts)

How important is weight?Jeff Rage
May 30, 2003 9:03 PM
I'm looking to get a halfway decent bike to ride when the trails are too wet for Mtn. Biking. (I made the previous post about finding a bike for a short guy.) I found a used bike that I like, but was concerned that it was 21 lbs. Is this heavy for a road bike? One of my frineds that I'll be riding with is getting one that's 18 lbs. Will I have trouble keeping up with him, simply because of the weight difference? Or is it more riding skill/conditioning?

BTW, finding a bike that will fit me isn't going to be easy. I barely fit over a Giant TCR small (44 cm).
re: How important is weight?Bruno S
May 30, 2003 9:25 PM
21 lbs. is OK for a road bike. A bike 3 lbs. less is really nothing. 1-2% weight decrease of the whole package: rider + bike. Riders like Armstrong can output 450 watts continuously versus average humans than can manage 150-200 watts. That's more than 100% difference. You do the math about what is more important weight or conditioning.
re: How important is weight?Jeff Rage
May 30, 2003 9:45 PM
Are you serious? How do I measure my wattage? :D)
These guys have all the answers ...Humma Hah
May 31, 2003 10:37 AM
... probably more than you want to know. I'll guarantee you that the top racing teams DO want to know all this stuff.

Some physics or engineering mechanics background will help. Analytic Cycling does everthing in SI units (meters, seconds, kilograms, watts ...). Instead of mph or kph, they'll work in meters per second, so have a calculator handy and know how to convert units.

They're selling devices like Power-Tap (there's a competing product called SRM), that measures torque at the rear wheel or crank, and RPM, to measure power directly. However, they provide a number of analytical tools that allow you to estimate your power by such things as your speed on known uphill grades. Very scientific stuff.

http://analyticcycling.com/
Running an example for 18 and 21-lb bikes ...Humma Hah
May 31, 2003 10:51 AM
I ran their basic model that calculates power from certain basic assumptions. I changed a few parameters:

150 lb rider with either an 18 or 21-pound bike, converting the total to kg.

A 10% grade, steep enough to qualify as greuling if it goes on for very long (Slope = 0.1).

A speed of 4 meters/second ... that's a very fast pace on that slope, and few here could sustain it for long.

With these fairly extreme conditions, the ligher bike would require 321.5 watts, the heavier 326.9 watts, a difference of 5.4 watts, or about 1.7% more power to ride the heavier bike.
Oops ... forgot the link to the model I used ...Humma Hah
May 31, 2003 10:54 AM
http://analyticcycling.com/ForcesPower_Page.html
Not much weight, not very importantRay Sachs
Jun 1, 2003 10:33 AM
Keep in mind that two water bottles will run about four pounds - do you feel any real difference riding with or without? I have a 22 pound bike and an 18 pound bike. I ride the 22 pounder about 90% of the time because it fits better and is more fun to ride. I can feel a difference on really steep climbs, but that could be geometry as well. For the kind of club rides and solo rides I do, it's a total non-issue.

Even racing, unless you're riding at a pretty high level and riding courses with a LOT of climbing, it won't make much difference.

-Ray
It's all mental...Matno
May 31, 2003 3:56 AM
Well, not really, but 3 lbs is a noticeable difference. It's also on the heavy side for a bike that small. As long as you're not racing, a 21 lb bike shouldn't cause any problems. I think my old Schwinn weighed 22, and I never had a problem with keeping up (in the 10 years I had the bike). However, now that I've switched to a lighter bike, the difference is very noticeable. One problem you might run into with a heavier bike (assuming it has the same components as a lighter one) is that the frame will likely be stiffer. My steel Schwinn was MUCH stiffer than my new Cannondale. The whole "steel is real" argument really only applies to lightweight flexible steel, not heavy straight-gauge steel like many of the less-expensive/heavier ones. If the heavier frame is good at absorbing road vibration, on the other hand, I'd say that's more important than the weight itself...
Not all that long ago......Walter
May 31, 2003 4:26 AM
the Euro peloton rode 21# bikes over Mt. Ventoux and the cobbles in the Ardennes and everywhere else they raced and they did it about as fast as today's pros today are doing it on 16-17# bikes.

If the bike is of good quality, in good shape, priced right and, most importantly, fits you the 21# is the LEAST significant factor involved.
No problem for your size, you've got most beat by 20# IMHO. nmSpunout
May 31, 2003 5:28 AM
3 lb= no difference, but a great excuse if you're slower nmContinental
May 31, 2003 6:19 AM
re: How important is the color?Jeff Rage
May 31, 2003 7:18 AM
The bike was a 1999 or 2000 Giant TCR2T. Components are a re mix of Shimano RSX and Shimano 105. I may be able to get it for under $500. HOw's that sound?
re: How important is the color?KG 361
Jun 1, 2003 12:53 PM
A little too much, I think. That bike new couldn't have sold for more than $1k with that mix of components. I'd say $400 would be more like it.
For smaller riders, somewhat important, but not too much.AllUpHill
May 31, 2003 8:16 AM
The difference between your purchase candidate and your buddy's bike will absolutely not give you "trouble keeping up with him." Your conditioning versus his is far more significant than 3 pounds. Don't worry about it.

However, some here will say that bike weight is not important at all. I claim that it can be important, especially for lighter riders like myself (and I assume you too). Of course, we featherweights tend to be better than average climbers to begin with.

I own a 22 pound bike for every day riding, and a 15.4 pound bike (getting lighter every few months ...) for events. I notice a big difference between the two. To give some objective data, some time soon I want to make a comparison of my times on local climbs for each. I'm sure the difference in time will be more than 10%. But again, I'm talking about a 7 pound difference. And this is only something to think about if you compete a fair amount, work hard on your climbing strength, and just plain enjoy throwing money at your bike -- the engine is much more important than the bike.
My two bikes: 24 lbs and 44 lbs ...Humma Hah
May 31, 2003 10:07 AM
I can tell I'm on the heavier one when I'm climbing, but even that much (more extra weight than carrying an extra roadbike) ain't too bad: The overall climbing weight of rider plus bike, in this extreme example, is around 10% more than with the lighter bike, and weight is really only important when climbing (roadbikes don't spend as much time accelerating as MTB's do).

Obsessing over grams is insane: the difference is inperceptible. Knocking pounds off a racebike makes sense ... the difference will show up if you're riding against other riders, where a 0.01 mph difference in speed may make the difference of several finishing places.

Sport riders with a bike 3 lbs heavier than their riding buddies should quit worrying and pedal just a tiny bit harder. Worrying about weight on a bike ridden primarily for exercise is a fool's errand. The heavier, the better.

That 21-pound bike is a full three pounds lighter than my fixed-gear Paramount, which I call my lightweight bike.
climbing versus flats.....rrjc5488
May 31, 2003 10:27 AM
If you live in a hilly area and are going to be climbing alot, then weight does matter, but if you're not racing, then you'll be fine. If you live in a flat area then aerodynamics will be more of an issue then weight. I'd invest in a nice pair of aero bars for flat roads.
Oh, l forgot...rrjc5488
May 31, 2003 10:32 AM
Adding up all the weight on lances TT bike, its probably about 22-23 lbs (disc wheels, hed 3, vision tech bars, aero frame... the works) and his pace is 32 mph for a TT. that insane, but agreeing with the earlier replies: its the motor not the machine. train harder than he does
Death rattlefiltersweep
May 31, 2003 10:59 AM
For all the hand wringing about how weight is completely over-rated, people spend thousands of dollars to shave the grams off their rides.

One issue to consider is that typically a lighter bike IS a better bike, or at least it has better components. If you are accustomed to a top-end mtn bike, you might be disappointed with a lower end group.

Conversely, that 21 lb bike you found may well have been advertised as an 18 lb bike. Bikes have a way of gaining weight when they are actually rideable. You might end up with the same weight as your buddy's bike.
re: How important is weight?kanekikapu
May 31, 2003 11:31 AM
pick the two out of the three: lightweight, stiff, cheap.

well if you thinking about that 3 lbs during your ride would definitely slow you down, like the other guy had point out, lost some weight instead of weight from the bike, it's cheaper, and much beneifical
re: How important is weight?EdSned
Jun 2, 2003 2:44 AM
very important - I live on the fith floor with no lift....

riding - forget it, if you every carry water.