# Does a 2 lb difference in bike weight...



## jspharmd (May 24, 2006)

...really improve performance?

So, on a recent thread it was mentioned that one difference between two bikes being discussed was a 1-1.5 lbs. This was met with comments from others that the weight of a bike is not that big of a deal. One poster stated that their fastest times have been on their heavy steel bike.

I own two bikes a Felt F65 (full Ultegra, Neuvation R28 Aero wheels) and a Kuota Kredo (full Dura Ace, Mavic Ksyrium ES wheels). They are set up exactly the same (had a professional fit on both bikes). I have noticed a large difference in my performance and fatigue when riding the two bikes. These have been group rides and solo rides on the exact same course with very similar temperatures and wind. The solo rides were done as my attempt to do two time trials on my own. 

Yesterday I had a chance to weigh the bikes and the Felt came in at ~18.4 lbs and the Kuota at ~16.4 lbs. 

My questions: 1) Can this difference in fatigue and performance be due to 2 lbs? 2) Is it related to the bike geometries (fairly similar)? OR 3) Is it totally psychological and I just feel faster on the Kuota? I will say that I really like both bikes and enjoy riding both.


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## CurbDestroyer (Mar 6, 2008)

In short the answer is "No".and "Yes" it's in your head . . . 2Lbs.is like adding 2 full water bottles. Next time you do that ride carry a couple water bottle in your jersey pockets and see what happens.

Your brain is a funny component . . . sometimes it can convince us of anything, no matter how illogic. This is mostly due to the way bicycle parts are marketed to us. Light is better.


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## FatTireFred (Jan 31, 2005)

how long of a ride? and how much of a difference in your "performance and fatigue"? people often complain of a frame "beating them up", so perhaps it's possible that the frames are contributing, but it's not the 2lbs


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## AlexCad5 (Jan 2, 2005)

The biggest difference in performance is the rider. You will perform at different abilities on different days.


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## FatTireFred (Jan 31, 2005)

AlexCad5 said:


> The biggest difference in performance is the rider. You will perform at different abilities on different days.




I suppose a 2 lb difference CAN make a diff in the case of the rider being in really really sorry conditioning, even then not sure it would be huge


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## Tri Slow Poke (Jul 22, 2006)

I think it's in your head. I have Trek aluminum TT bike and a carbon Kuota TT bike. Not putting either on a scale, I could tell the Kuota was lighter and I really WANTED it to be "faster". Lo and behold, the Trek outperformed the Kuota becasue it fit me better and was more suited to my riding style.


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## buck-50 (Sep 20, 2005)

My cyclocross bike weighs around 18 pounds. My rivendell weighs close double that.

the biggest gear on my CX bike is a 39/12, the biggest on the riv is a 48/12.

The cx bike is faster over the same course, even with the lower gears. BUT: that really has nothing to do with weight and everything to do with how I ride the CX bike- Aggressive and hard. The riv, I ride it a lot more laid back- stainless steel fenders will do that to you...


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## android (Nov 20, 2007)

jspharmd said:


> Yesterday I had a chance to weigh the bikes and the Felt came in at ~18.4 lbs and the Kuota at ~16.4 lbs.
> 
> My questions: 1) Can this difference in fatigue and performance be due to 2 lbs? 2) Is it related to the bike geometries (fairly similar)? OR 3) Is it totally psychological and I just feel faster on the Kuota? I will say that I really like both bikes and enjoy riding both.


You're not really calculating the weight difference correctly.
The correct calculation would be (your weight) + (weight of shoes, helmet, stuff in pockets) + (weight of patch kit/extra tubes) + (weight of water bottles) + 16.4 or 18.4

then you can figure out the real % difference it the total weight you have to haul around. Let's say you come up with 160 and 162 lbs, then 2 / 160 * 100 = 1.25% total difference in weight between the two scenarios. 

As you say you notice a "large difference" in performance, I don't believe it can be rationally explained by a 2lb difference in the weight of the bikes.

Other contributing factors could be psychological or due to frame or wheel stiffness and ride qualities. Some bikes or wheels rider harsher and this can take it out of you. You could try swapping wheels between the two bikes and see if you experience any noticeable difference.


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## MIN in PDX (Nov 29, 2007)

When I got Zipp tubulars, it was noticeable - particularly on climbs. I was coming off of a 2100 gram wheelset. (1.1 pound reduction)

When I dropped 1 pound from other areas of my bike, I didn't notice it.


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## jspharmd (May 24, 2006)

I thought it might just be in my head. Thanks for all of the great responses.



> FatTireFred: how long of a ride? and how much of a difference in your "performance and fatigue"?


Sorry, I forgot to put this information in the original post, but I don't have the exact times in my head, the solo ride is approximately 20 miles and the avg mph difference was about 0.75 mph. 


Maybe the word fatigue is incorrect, I just feel like I could go all day on the Kuota, whereas the Felt feels like I'm working harder to achieve the same result. This was a big factor on the two rides. The thing is, I really wanted them to at least feel the same (I'm new to racing and use the Felt in Cat 5 races). The different feel of the bikes has been evident on other rides. I don't feel beat up by the Felt, just different. The thing is, I didn't think the weight difference was that much. 

As far as conditioning goes, I'm not the fittest person on rides, but I can keep up with most on group rides (a couple of Cat 3 guys are too fast for me).


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## jspharmd (May 24, 2006)

MIN in PDX said:


> When I got Zipp tubulars, it was noticeable - particularly on climbs. I was coming off of a 2100 gram wheelset. (1.1 pound reduction)
> 
> When I dropped 1 pound from other areas of my bike, I didn't notice it.


This makes sense based on the rotational weight threads I've seen.
So why did you drop the pound from other areas of your bike?


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## MIN in PDX (Nov 29, 2007)

jspharmd said:


> So why did you drop the pound from other areas of your bike?


Why not? 

I actually dropped a over 4 pounds from stock.


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## ghostzapper2007 (May 22, 2007)

jspharmd said:


> This makes sense based on the rotational weight threads I've seen.
> So why did you drop the pound from other areas of your bike?



No it really does not. Rotational weight is one of the most wildly misunderstood and also overated characteristics of bike performance, as are almost all other marketing claims about bike performance and its related equipment. It takes extremely small differences in energy input by the rider to rotate bike wheels of different weights, even those that are 1 lb different in weight. Even a 1 lb difference in wheelset weight results in only about a 220 gram differece per wheel and a lot of that weight savings I'll gurantee is in the use of superlight hubs in the ultralight wheelset which has no impact at all on rotational weight. Lighter spokes also has almost no impact on effective rotational weight differences. Plus, you spend very little of your ride actually accelerating your wheel bigtime, certainly not from a stop many times on most group rides and races. Even accelerating a bike wheel from a complete stop takes very little energy input by the rider to accelerate the wheel itself, physics and pure mechanics backs this up. It just does not take a whole lot of energy to accelerate a bike wheel, and in particular, the amount of energy needed to be input is essentially next to microscopic for a wheel already in motion which is now being accelerated to a slightly higher speed. Bike marketing majors have sold lots of people on a performance enhancing bill of false goods for years convincing them they need $2000 tubular race wheelsets and vada vrooooom suddenly they'll go lots faster. One could not make a more nonsenseical claim. The aero advantages of super expensive wheels typically far outweighs any rotational weight performance advantage and even these aero advantages are not going to tranform you many mph faster as a rider. But if the claims keep the clueless weight weenies and the easily fooled giddy, so be it.


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## azchris (Oct 17, 2007)

Every time there is a thread started about the difference in a few ounces or pounds the responses start with "...makes no difference. It is the conditioning of the rider and the rider's ability." Then the posts eventually get around to pontificating about aerodynamic spokes or the rolling resistance of different tires or other such stuff etc. Makes me wonder if anyone knows what they are talking about or if they just have their favorite theories that they like to espouse.


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## Bob Ross (Apr 18, 2006)

azchris said:


> Every time there is a thread started about the difference in a few ounces or pounds the responses start with "...makes no difference. It is the conditioning of the rider and the rider's ability." Then the posts eventually get around to pontificating about aerodynamic spokes or the rolling resistance of different tires or other such stuff etc. Makes me wonder if anyone knows what they are talking about *or if they just have their favorite theories that they like to espouse*.


Well, irrespective of your questioning whether anyone knows what they're talking about, I agree that we all seem to have our own personal "angle" that we approach these discussions from. For example, everytime I contribute to a thread about bike weights it's to remind people that regardless of whether there are perceivable/demonstrable performance advantages to a lighter bike, there is one inarguable difference:

_It's lighter!_

Which is definitely an advantage if you ever have to lift your bike. Which I seem to do way too often to not make weight at least a consideration when comparing bikes.

I currently own 2 bikes: One weighs just under 23lbs, the other weighs somewhere around 17lbs. Neither bike goes faster than the other...on the road But one of them sure goes faster when I'm lifting it overhead to hang from the ceiling hooks!


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## vanjr (Sep 15, 2005)

was that from your propad? what does it weigh now?


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## DrSmile (Jul 22, 2006)

It makes no difference for me. It does feel like I go up the hills faster with the lighter bike, but somehow it gets evened out on descents and flats. There is a 4 pound difference between my old and new bike too, and the new bike has much lighter (almost 500g!) wheels.


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## MIN in PDX (Nov 29, 2007)

vanjr said:


> was that from your propad? what does it weigh now?


You mean mine? It's under 18 pounds now with Zipps and about 19 pounds with clincher wheels.


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## danl1 (Jul 23, 2005)

Of course weight matters, just not for all that much. And raw physics aside, wheel weight 'matters' a bit more than regular dead weight - not so much in overall performance as conservation of momentum is real, but that it's a tad more noticeable, so it effects your mind differently.

As for the particular circumstance, it's as likely that particulars of the bikes riding and handling characteristics matter as much or more to your feeling of 'going on all day' than the weight. Same thing is true for performance. For example, let's compare a bike typically designed for crits (tight wheelbase, stiff drivetrain, steep angles, fast steering) with one more intended for stage racing (a bit down each of those scales.) It's not hard to picture one 'beating you up' more, from the stiffness, but that's only the start. The tighter steering on the crit bike will also require more input and attention, which has both physical and mental demands. But it's not done yet. Those constant small changes to steering scrub a tiny amount of speed, and also take a slightly longer line than a bike that's running smooth and steady. All told these things make for a bike that over distance can both feel and be slower, even though it's the fastest tool for it's designed mission.

Then we can layer all the differences in build, materials and componentry, and the slight changes in fit that might be involved. Fit is a funny thing. We can adapt to some fairly significant changes in distances without much notice, but sometimes small changes in saddle angle or type can have impressively large effects. 

The folks who say weight doesn't matter are flat-out wrong, especially if any sort of terrain is involved. But it matters a fair bit less than most every other factor in bike performance.


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## MIN in PDX (Nov 29, 2007)

danl1 said:


> Of course weight matters, just not for all that much. ...



I agree with your assessment. When I moved from 44cm winter bars to 40cm "fair weather bars" my crusing MPH went up a full MPH, all else equal. Rider aerodynamics and fit matters more than a couple of pounds but it's nice to have a lighter bike, particular since I climb so many hills.


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## mendo (Apr 18, 2007)

*2 lbs makes a difference*

As illustrated above, the difference in rider plus bike weight will likely be ca. 1%. That's the difference. You will climb imperceptibly faster on the lighter bike, all things being equal, i.e. Bike X vs. Bike X with 2 pounds of weights in the seat tube.


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## dahowe (Aug 12, 2007)

I will take a reduction of 2 lbs (10-15%) of unsprung weight each and every day. No questions asked.


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## Creakyknees (Sep 21, 2003)

Ok.. nobody's addressed bike fit yet. 

"Geometry" of the bike is one thing, fit is quite another. Have you taken a tape measure, bubble level and t-square to both bikes and confirmed they are exactly the same? If you want to rule out variables, that's a biggie.


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## goldsbar (Apr 24, 2002)

What does unsprung weight have to do with a road bike? There's no suspension outside of the tires. Can you take 2 pounds off of tires?


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## azchris (Oct 17, 2007)

There is no doubt that all of these things will have some kind of effect whether it be weight, aerodynamics, tire characteristisc, etc, etc. This would matter to an elite athlete conditioned to a razors edge. But for most of us this is not the case; heck, my body weight probably varies more than 2 pounds from week to week.

So, it is fun to discuss the different way to improve performance but within some reasonable boundaries,for the vast majority it is acadamic and/or psychological satisifaction.


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## sokudo (Dec 22, 2007)

It should be pretty easy to make it a controllable experiment. Add 2 lbs to Kuota Saddle bag with sand or large water bottle with water should suffice. Do several runs in random order with and without extra weight. Throw into the mix a run or two on Felt. Report results.


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## jspharmd (May 24, 2006)

Creakyknees said:


> Ok.. nobody's addressed bike fit yet.
> 
> "Geometry" of the bike is one thing, fit is quite another. Have you taken a tape measure, bubble level and t-square to both bikes and confirmed they are exactly the same? If you want to rule out variables, that's a biggie.


Due to slightly different geometries there are differences - like stem length, but the guy at the shop set-up both bikes and measured both bikes. They have the same measurements from seat to pedal, seat to handlebars, and all other measurements with me on the bikes. I'm not sure what they all are, but everytime a measurement was taken they were very close.

In a double-blinded, randomized controlled trial the power of placebo has to be taken into consideration. The mind is a powerful thing, and I guess much of the perceived difference is in my head. 

Now explain to me why people are constantly upgrading their bikes and trying to reduce the weight.


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## SleeveleSS (Jun 3, 2007)

ghostzapper2007 said:


> No it really does not. Rotational weight is one of the most wildly misunderstood and also overated characteristics of bike performance, as are almost all other marketing claims about bike performance and its related equipment. It takes extremely small differences in energy input by the rider to rotate bike wheels of different weights, even those that are 1 lb different in weight. Even a 1 lb difference in wheelset weight results in only about a 220 gram differece per wheel and a lot of that weight savings I'll gurantee is in the use of superlight hubs in the ultralight wheelset which has no impact at all on rotational weight. Lighter spokes also has almost no impact on effective rotational weight differences. Plus, you spend very little of your ride actually accelerating your wheel bigtime, certainly not from a stop many times on most group rides and races. Even accelerating a bike wheel from a complete stop takes very little energy input by the rider to accelerate the wheel itself, physics and pure mechanics backs this up. It just does not take a whole lot of energy to accelerate a bike wheel, and in particular, the amount of energy needed to be input is essentially next to microscopic for a wheel already in motion which is now being accelerated to a slightly higher speed. Bike marketing majors have sold lots of people on a performance enhancing bill of false goods for years convincing them they need $2000 tubular race wheelsets and vada vrooooom suddenly they'll go lots faster. One could not make a more nonsenseical claim. The aero advantages of super expensive wheels typically far outweighs any rotational weight performance advantage and even these aero advantages are not going to tranform you many mph faster as a rider. But if the claims keep the clueless weight weenies and the easily fooled giddy, so be it.


Do you have any sources for these claims?


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## ghostzapper2007 (May 22, 2007)

SleeveleSS said:


> Do you have any sources for these claims?


Do you have any sources for counter claims from "legitimate sources"? I'm not your paid personal librarian, you can do your own research.


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## Bob Ross (Apr 18, 2006)

jspharmd said:


> Now explain to me why people are constantly upgrading their bikes and trying to reduce the weight.




Um...it's called a "hobby"


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## SleeveleSS (Jun 3, 2007)

ghostzapper2007 said:


> Do you have any sources for counter claims from "legitimate sources"? I'm not your paid personal librarian, you can do your own research.


I'm not disputing you or making any claims, so I don't need sources. You are making claims and therefore should have some references if you expect anyone to take you seriously. Are you just an "internet rider" who regurgitates what he once heard a 2nd rate bike mechanic say at a coffee shop, or have you actually done some research to come to these conclustions. I'm not asking you to be my personal librarian, just back up what you're claiming with some facts.


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## ghostzapper2007 (May 22, 2007)

danl1 said:


> Of course weight matters, just not for all that much. QUOTE]
> 
> 
> Correct, of course going uphill with a slightly lighter object is easier than doing so with a heavy object. The degree of so called improvement from minor weight savings is what is at issue, not that it has no relevance at all. Whenever I hear someone claim they just tried a new component or dropped a bit of weight off their bike and now they are riding effortlessly or much faster I know the BS meter is working overdrive. No small weight change (and yes 2 lbs is a small change when you consider the weight of the rider, complete bike, water bottles, riders outfit, etc) is going to suddenly make you Lance Armstrong or advance to the next CAT level by majic. I don't think anyone who has graduated from high school would truly believe there is ZERO difference in riding a slightl;y lighter bike, just that the difference is far below the weight weenie exagerated claims which abound in here. :-0


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## jspharmd (May 24, 2006)

Bob Ross said:


> Um...it's called a "hobby"


So you go around making things lighter as a "hobby". How much does your car weigh? How much do your running shoes weigh?


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## ghostzapper2007 (May 22, 2007)

SleeveleSS said:


> I'm not disputing you or making any claims, so I don't need sources. You are making claims and therefore should have some references if you expect anyone to take you seriously. Are you just an "internet rider" who regurgitates what he once heard a 2nd rate bike mechanic say at a coffee shop, or have you actually done some research to come to these conclustions. I'm not asking you to be my personal librarian, just back up what you're claiming with some facts.


No not really, just like I don't need specific sources to claim an object will fall from my hand if I drop it off a roof. I don't need a specific source to know if you are a mediocre CAT 5 rider on an 18lb bike that you sure as heck are not suddenly going to be riding at the CAT 4 level because you dropped your component weights by 2 lbs. There is more than enough "empirical" evidence available throughout cycling history for one to already know this as factoid! There is more than enough available evidence regarding bike performance for the masses (at least the SANE masses) to understand that slight weight changes in ones bike equipment has extremely small effects on ones bike riding performance. It doesn't suddenly give you a new engine and make you ride MPH's faster! And again, I'm not anyones personal librarian, nor will I attempt to be as much as you would like me to do so. Sorry, I don't play that game.


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## SleeveleSS (Jun 3, 2007)

ghostzapper2007 said:


> No not really, just like I don't need specific sources to claim an object will fall from my hand if I drop it off a roof. I don't need a specific source to know if you are a mediocre CAT 5 rider on an 18lb bike that you sure as heck are not suddenly going to be riding at the CAT 4 level because you dropped your component weights by 2 lbs. There is more than enough "empirical" evidence available throughout cycling history for one to already know this as factoid! There is more than enough available evidence regarding bike performance for the masses (at least the SANE masses) to understand that slight weight changes in ones bike equipment has extremely small effects on ones bike riding performance. It doesn't suddenly give you a new engine and make you ride MPH's faster! And again, I'm not anyones personal librarian, nor will I attempt to be as much as you would like me to do so. Sorry, I don't play that game.


You should reread your original post if you have forgotten what you claims were. You did not make a generic claim that dropping weight wouldn't move you up a category instantly. You made specific claims that aero makes more of a difference than weight, that lighter spokes has almost no impact on rotational weight differences, very little energy input to accelerate the wheel, etc. Again, these claims are specific and not general "MPH's faster" statements. 

You can call backing up your claims being a "personal librarian" if you want. There are people who actually research the facts, and then there are those that regurgitate or make stuff up and hope others believe them. If you weren't talking out of you ass, you would be able to back your claims up with data, but since you apparently can't I can just disregard your posts and assume you fall in the latter category. Thanks.


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## Kerry Irons (Feb 25, 2002)

*Physics 101*



SleeveleSS said:


> Do you have any sources for these claims?


Sources = first year physics class. BTW, the way technical arguments work is that the one who claims the big effect has to prove it, especially when the fundamentals don't support the claim. The person stating the base case from fundamentals doesn't have to "prove" anything. The person with the outlandish claims does. Just saying.

Here's some actual numbers: for a 150 lb rider on a 6% grade putting out 250 watts, adding 2 lbs results in a 0.2 mph penalty. That translates to about 1000 feet (320 meters) gained over an hour of riding. However, on a flat road at the same power output, the speed difference is 0.035 mph, which is a gap of 184 feet per hour. A good set of aero wheels will be worth nearly 10 times that speed improvement.


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## ghostzapper2007 (May 22, 2007)

Kerry Irons said:


> Sources = first year physics class. BTW, the way technical arguments work is that the one who claims the big effect has to prove it, especially when the fundamentals don't support the claim. The person stating the base case from fundamentals doesn't have to "prove" anything. The person with the outlandish claims does. Just saying.
> 
> Here's some actual numbers: for a 150 lb rider on a 6% grade putting out 250 watts, adding 2 lbs results in a 0.2 mph penalty. That translates to about 1000 feet (320 meters) gained over an hour of riding. However, on a flat road at the same power output, the speed difference is 0.035 mph, which is a gap of 184 feet per hour. A good set of aero wheels will be worth nearly 10 times that speed improvement.


Yep, what you said!

I'll challenge anyone out there to show a marked MPH improvement in their speed over any varying terrain by reducing their bike or even specifically their wheelset weight by a mere 2 lbs. It's a bogus claim that flys directly in the face of proveable physics, and even as important, well documented empirical data regarding cycling races and group rides which has been around for decades. But weight weenies need to convince themselves their $500 brakes saving 100 grams in weight are making them lots faster. The marketers love these gullible fellows.


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## Art853 (May 30, 2003)

Mark McM works out some examples of rotating and non rotating mass

http://weightweenies.starbike.com/forum/viewtopic.php?t=6394&postdays=0&postorder=asc&start=45


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## Forrest Root (Dec 22, 2006)

SleeveleSS said:


> I'm not disputing you or making any claims, so I don't need sources. You are making claims and therefore should have some references if you expect anyone to take you seriously. Are you just an "internet rider" who regurgitates what he once heard a 2nd rate bike mechanic say at a coffee shop, or have you actually done some research to come to these conclustions. I'm not asking you to be my personal librarian, just back up what you're claiming with some facts.


Posted here and at Weight Weenies are equations of motion for a bicycle. Solve those equations using whatever initial conditions tickle your fancy, and you'll see, as the equations show, that rotational weight is not the big influence people allege it to be. In fact it doesn't become the dominant influence on bike acceleration until the road grade exceeds 9-10%, and then it only dominates because velocity has decreased so much. 
Even when it dominates, it's not huge.


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## Forrest Root (Dec 22, 2006)

azchris said:


> Every time there is a thread started about the difference in a few ounces or pounds the responses start with "...makes no difference. It is the conditioning of the rider and the rider's ability." Then the posts eventually get around to pontificating about aerodynamic spokes or the rolling resistance of different tires or other such stuff etc. Makes me wonder if anyone knows what they are talking about or if they just have their favorite theories that they like to espouse.


There are no "favorite" theories. There are models which are based on several hundred years of vetted physical laws and theorems, and then there are make believe things, false theories.

The basis for accepted physical laws is a simple google search away. Two good sources for learning some of the stuff is the Hyperphysics website and Wikipedia. There are others that go into more or less depth.

As for who has the burden of proof, it's as Kerry said. If what someone suggest is new to science or goes against what is accepted, they have to prove their "claim." Every time someone mentions the speed of light, that person isn't bound to also discuss how everyone from Michelson and Morley to scientists today have proven there is no "luminiferous aether" and subsequently defined the speed of light. Likewise, construction of an equation of motion for a bicycle/rider system is essentially trivial. There is no new knowledge needed to do it, nor is there any dispute of whether it's correct or not. From there, it's just plug and chug.


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## Forrest Root (Dec 22, 2006)

jspharmd said:


> So you go around making things lighter as a "hobby". How much does your car weigh? How much do your running shoes weigh?


Uhm, did you intentionally misread what he said? For the record, yes it is a "hobby." More accurately though, it's a challenge to quite a few cyclists to build a bike and then to see how much you can lighten said bike while still having something everday rideable. Some want to lighten to see just how low they can go, the rideability be damned. In case you haven't been paying attention similar sorts of enthusiasts do similar things to cars, boats, motorcycles, lawn mowers. In fact, there is a whole website.....wait...wait......here it comes......called Weight Weenies where these sorts of things have been discussed for years. Imagine that.


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## quickfeet18 (Mar 2, 2007)

No one would care about bike weight if it didn't make a difference. Pros wouldn't jump off their bikes and switch to lightweight bikes for the mountains if it didn't. it is tiny but it is there. Power to weight ratio, when you cannot take anymore off your self, take it off your bike

As far as aero, the MIT cycling team(who have their own wind tunnel) said a few years ago that not wearing gloves in a tt makes more of an aerodynamic advantage than deep section wheels so you can't tell me that minute changes in your bike and your clothes don't make any difference at all.

also here is some math for you dorks who love to sit around counting and calculating.

http://en.wikipedia.org/wiki/Bicycle_performance


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## Forrest Root (Dec 22, 2006)

quickfeet18 said:


> No one would care about bike weight if it didn't make a difference. Pros wouldn't jump off their bikes and switch to lightweight bikes for the mountains if it didn't. it is tiny but it is there. Power to weight ratio, when you cannot take anymore off your self, take it off your bike
> 
> As far as aero, the MIT cycling team(who have their own wind tunnel) said a few years ago that not wearing gloves in a tt makes more of an aerodynamic advantage than deep section wheels so you can't tell me that minute changes in your bike and your clothes don't make any difference at all.
> 
> ...


There is a difference between making a difference and being insignificant. Of course there's a difference, but if that difference, say, only becomes apparent at the 10th decimal point? Is that a difference worth noting?

As for the pros, well that's a whole different thing. Pros do lots of things for lots of reasons, many of them for reasons that really do nothing. Also, they're getting paid to win. The team is getting paid, by the sponsors, to get the sponsors' names in the lights, which requires doing well. If the money's there, and using something lighter has no significant downside, then they might just do that. It doesn't hurt, right? Your assumption, though, about weights of Pro Tour bikes is not exactly on the mark.
I just recently read an article on one of the popular online cycling rags, wherein a reporter weighed a bike from each of the teams at a race. The weights ranged from 'round the 6.8 kg (14.96lbs) UCI weight limit to the porkiest which was Eric Zabel's at 'round 8 kg (17.7ish lbs). Whoda thunk it.


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## quickfeet18 (Mar 2, 2007)

Eric Zabel's bike probably isn't designed to ride the fastest in the cols where weight is most important. I am sure that at that end of the spectrum riders like Zabel have chosen for a little bit lighter weight in the name of a stiffness advantage. I am also 100% sure that if someone could make Zabel a bike that would weight 14.96lbs and was just as stiff and as strong as his current 17.7lb bike he would take it in a heartbeat. 

Even if it is a small difference it is still a difference and is something that should be considered by riders looking to perform their best. Just because the way your jersey looks is insignificant doesn't mean it isn't something you consider when you purchase it. Anyone who races has a chance to get paid to win too, I know most races have a purse to at least get some of your money back. Is that not motivation enough for you to try and do your best with every aspect of your game no matter how insignificant?


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## Forrest Root (Dec 22, 2006)

quickfeet18 said:


> Eric Zabel's bike probably isn't designed to ride the fastest in the cols where weight is most important. I am sure that at that end of the spectrum riders like Zabel have chosen for a little bit lighter weight in the name of a stiffness advantage. I am also 100% sure that if someone could make Zabel a bike that would weight 14.96lbs and was just as stiff and as strong as his current 17.7lb bike he would take it in a heartbeat.
> 
> Even if it is a small difference it is still a difference and is something that should be considered by riders looking to perform their best. Just because the way your jersey looks is insignificant doesn't mean it isn't something you consider when you purchase it. Anyone who races has a chance to get paid to win too, I know most races have a purse to at least get some of your money back. Is that not motivation enough for you to try and do your best with every aspect of your game no matter how insignificant?


Well, what you're saying is a viewpoint or maybe even a strategy. It's not a fact based on technical factors. I'll guarantee you that on the mountain stages, not every bike in the peloton is at 6.8kg. I'd wager to say that there is at least a 0.4 to 0.5 kg range of values, if not more. Also, such small differences are often lost in the "noise." That is to say that they're so small that they're lost in random values, from other sources, that have a standard deviation greater than or equal to that small difference. Right now I've got an instrument on my lab bench that measures to 12 picometers. That's danged small. However, right now, in the lab, the noise level is 100 nanometers RMS, 8333 times larger than that instrument's resolution. So, we can't make a measurement and say, "Look, that distance was 104 picometers," because the noise is so much greater. And what would "noise" be in a race situation like what you propose? It could be a gust of wind, variances in pavement, a bit of gravel or oil on the road, a bunged up gear shift, a wrong gear, hitting a knee on a handlebar drop, a cough, a look the wrong way, and so on. It could be any number of things. And many of those things are happening on the way to every photo finish.

If you want to make a technical point, you'll have to pull up some facts.


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## dahowe (Aug 12, 2007)

goldsbar said:


> What does unsprung weight have to do with a road bike? There's no suspension outside of the tires. Can you take 2 pounds off of tires?


Ever notice how much better it is when you ride over a really crappy patch of road or a root infested MUT to sit up off the seat? The reason it is better is that you are using your legs and arms as springs for the huge mass proportion of the bike rider combo. All weight not sprung has a direct and significant impact (punn intended) on how the bike rides over inconsistencies in the road. A lighter bike has less weight (inertia) to deal with on each of those impacts. And yes it is very much at play while seated as well. 

Although seldom talked about I believe it is one of the 'intangible' reasons why people say "I don't know why but it just seems that the lighter bike was more fun/easier/quicker, etc to ride".


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## gregwjs (Nov 9, 2007)

None of this would matter if you guys would avoid competitive time trials. 

wheelsucking>aero>>lightweight>stiffness



I have no data to back that up though.


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## danl1 (Jul 23, 2005)

quickfeet18 said:


> I am also 100% sure that if someone could make Zabel a bike that would weight 14.96lbs and was just as stiff and as strong as his current 17.7lb bike he would take it in a heartbeat.


And you might be entirely incorrect. The reason he made the choices he did may very well have nothing at all to do with stiffness or strength - in fact, it's entirely possible that part of the dynamic was to avoid some amount of stiffness. He's on that damn thing all day, every day, and comfort is a critically important part of overall performance. 

Building a light, stiff bike is relatively trivial. Building a light, stiff, comfortable bike is quite elusive. That famed 'vibration damping' quality of CF only comes from excess epoxy in the layup, which adds weight and decreases strength, requiring still more material to compensate, increasing weight all the more.


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## Lifelover (Jul 8, 2004)

*Left over from another thread....*



ghostzapper2007 said:


> ..
> . I don't think anyone who has graduated from high school would truly believe there is ZERO difference in riding a slightl;y lighter bike, just that the difference is far below the weight weenie exagerated claims which abound in here. :-0



I do!

The weight difference between ceramic bearing and standard bearings will have ZERO net difference in a riders time!


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## quickfeet18 (Mar 2, 2007)

you seriously think that an elite sprinter wants a less stiff bike so that he can go for a leisurely afternoon ride with his friends? Doubtful 

mere mortals like you and me may look for a slightly heavier ride for comfort but I just don't think that is the case with pros


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## Forrest Root (Dec 22, 2006)

quickfeet18 said:


> you seriously think that an elite sprinter wants a less stiff bike so that he can go for a leisurely afternoon ride with his friends? Doubtful
> 
> mere mortals like you and me may look for a slightly heavier ride for comfort but I just don't think that is the case with pros


You'd be surprised. What source of information are you using that shows that stiffer bikes perform better? There has yet to be a study that draws a definitive correlation between frame stiffness and performance. You will find, though, that many studies have been done on how repeated impacts and vibrations of various frequencies increase muscle fatigue and can cause over-use injuries. Increased muscle fatigue correlates pretty directly with decreased performance.


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## quickfeet18 (Mar 2, 2007)

I know from personal experience, as a big 200lb sprinter myself flimsy frames with low stiffness hinder performance rather than help it. I concede that a more compliant frame is more comfortable, but for a sheer race perspective I want my bikes to be as stiff and light as I can get them. I do have to sacrifice some weight savings for a stiffer more responsive bike and I accept that. I have to have a 59cm frame so I am obviously not going to have a 14.96lb bike without sacrificing a lot of stiffness and strength. If I could get that weight and a stiff frame would I take it in a heartbeat. even though you may mot actually lose any power from a flexy frame the feeling of it is disconcerting for most people, which is why many bike manufacturers make stiff frames now.


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## jpap (Jun 21, 2006)

Forrest Root said:


> You'd be surprised. What source of information are you using that shows that stiffer bikes perform better? There has yet to be a study that draws a definitive correlation between frame stiffness and performance. You will find, though, that many studies have been done on how repeated impacts and vibrations of various frequencies increase muscle fatigue and can cause over-use injuries. Increased muscle fatigue correlates pretty directly with decreased performance.



Exactly my experience. My current ride is a Dean Titanium that comes in 2.5 pounds heavier than the aluminium DeRosa it replaced. The DeRosa was one very stiff frame. My usual weekend loop about 110kms is taking me less time on the Dean than the DeRosa of which I put it down to less muscle fatigue on the Dean therefore better performance towards the latter part of the ride.


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## Squidward (Dec 18, 2005)

My own experience is that a stiffer bike is faster even if it is heavier. I moved the components from an aluminum Leader frame over to a carbon fiber Pedal Force RS2 frame and the bike was about one pound lighter but my Garmin tells me that the lunchtime loop I used to ride was fastest on the aluminum frame. That aluminum bike was STIFF! That's why I got rid of it.


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## jpap (Jun 21, 2006)

Squidward said:


> My own experience is that a stiffer bike is faster even if it is heavier. I moved the components from an aluminum Leader frame over to a carbon fiber Pedal Force RS2 frame and the bike was about one pound lighter but my Garmin tells me that the lunchtime loop I used to ride was fastest on the aluminum frame. That aluminum bike was STIFF! That's why I got rid of it.



I'm guessing your lunchtime loop aint 110kms.


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## wankski (Jul 24, 2005)

Kerry Irons said:


> Here's some actual numbers: for a 150 lb rider on a 6% grade putting out 250 watts, adding 2 lbs results in a 0.2 mph penalty. That translates to about 1000 feet (320 meters) gained over an hour of riding. However, on a flat road at the same power output, the speed difference is 0.035 mph, which is a gap of 184 feet per hour. A good set of aero wheels will be worth nearly 10 times that speed improvement.


that's a pretty big gap for aero wheels... over an hour TT, u're saying wheels alone could help u gain 0.5km extra distance.... that's pretty impressive, even @ 40km/h that's worth at least 45sec... that won't save u being stomped on by an A grader, but that's a pretty handy gap over lesser competition...


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## djg (Nov 27, 2001)

No, I doubt very much it's the weight. Look, two pounds might make a marginal difference here and there. If you're trying to hang on, at your limit, on a tough climb, or constantly jumping on the pedals out of tight corners, then all things equal, a little lighter bike might make some sort of difference. But if we're talking average times over varied courses, or marked differences in energy consumption . . . well, no, I don't see it. 180 lbs bike + rider weight versus 178 pounds bike plus rider weight -- the weight alone is just not a huge deal. If they're really set up the same -- same contact points, same wheels, same tires, same pressure, then I can think of two possibilities. One is that the combination of frame design and saddle position on one of the bikes means that you're getting beat up more on bike A versus bike B, in a way that changes your performance. The other is that one bike really does not fit that well -- you've got the contact points right but your balance is off to the point where you're feeling more tense on corners, etc. Other than that, supposing nothing is broken, I'd guess the difference is at least partly in your head -- things feel a bit different, so your react to them differently -- can happen to any of us.


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## jspharmd (May 24, 2006)

Forrest Root said:


> Uhm, did you intentionally misread what he said? For the record, yes it is a "hobby." More accurately though, it's a challenge to quite a few cyclists to build a bike and then to see how much you can lighten said bike while still having something everday rideable. Some want to lighten to see just how low they can go, the rideability be damned. In case you haven't been paying attention similar sorts of enthusiasts do similar things to cars, boats, motorcycles, lawn mowers. In fact, there is a whole website.....wait...wait......here it comes......called Weight Weenies where these sorts of things have been discussed for years. Imagine that.


Maybe you misunderstood (or forgot the reason of this thread), my original post related to weight of a bike and speed/performance/feeling on a bike. 

Therefore my second question as to why people would try to lighten their bike was in reference to improved performance/speed/feeling on a bike. There are always threads that ask "What upgrade will provide the best benefit...” inevitably there are responses that boil down to weight. Maybe you have missed these posts. That is why I asked about people reducing the weight of their bike.

I may not have as much experience as you, but I do...wait for it...wait for it...wait for it...wait for it...okay...know why the weight weenies website exists. I realize that for some people it is a hobby, but in relation to performance (as the original thread was intended) it must go beyond a hobby to a level that people believe weight does matter. Otherwise, we would never see the post - those are decent wheels, but at 1600 grams they are pretty heavy.

So a response to my question that attempts to be witty, sarcastic, and elitist only shows that they misunderstood the question. Your defense of their comment only goes to show that more than one person doesn’t bother taking the time to read, think about, and then respond to a question. Rather, it is about jumping in and trying to show how smart you are, only to be defeated by your own lack of attention.

People, people, please try to stay on target here.


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## Forrest Root (Dec 22, 2006)

jspharmd said:


> Maybe you misunderstood (or forgot the reason of this thread), my original post related to weight of a bike and speed/performance/feeling on a bike.


I understood your post exactly. I told why some are concerned about weight. How many people think there are performance benefits to be had with frame or component weight loss? At WW, not many. Here, more than reasonable people would hope. 

Feeling? Well, if you want to know if people will do something for "feeling", as you just stated, well, of course. Close your eyes and pick a thread on RBR. Read it. You'll find that of course people will pick something based on feeling. 

What does feeling have to do with fact? Uhm, nothing.

As for your elitist comment, if it makes you feel better to think that, then good for you. Your assumption though is wrong, and you misread terribly.


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## Squidward (Dec 18, 2005)

jpap said:


> I'm guessing your lunchtime loop aint 110kms.


Not even close, but with plenty of climbing which favors less weight.


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## brentster (Jul 12, 2007)

Since its flat here and hills don't come into play riders get dropped when there is a hefty side wind and they're not able to draft. 

Head wind: Tuck in 6 inches off the wheel in front of you and you'll be okay.

Tail wind: That's where all the fun is and unless your group ride throttles past about 32 and you're lungs can't take it, you should be okay there too.

Cross wind: Especially coming from the left and your towards the back of the pack and unable to draft because everyone is shoved up against the grass. That's where people get dropped.

2 pounds isn't going to help you there. Its all up to you at that point.


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## Kerry Irons (Feb 25, 2002)

*Well documented*



wankski said:


> that's a pretty big gap for aero wheels... over an hour TT, u're saying wheels alone could help u gain 0.5km extra distance.... that's pretty impressive, even @ 40km/h that's worth at least 45sec... that won't save u being stomped on by an A grader, but that's a pretty handy gap over lesser competition...


It is well documented and widely reported by many different testers that the best aero wheels are worth 0.65 km/hr at 40 km/hr (0.4 mph at 25 mph) compared to 32 spoke, box section rims.


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## wankski (Jul 24, 2005)

whoa, saving a minute off your TT is pretty cool. hrmm... should get onto those carbons before next season then ! heh...


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## Bob Ross (Apr 18, 2006)

jspharmd said:


> So a response to my question that attempts to be witty, sarcastic, and elitist only shows that they misunderstood the question.


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