Why are heavy aero wheels so expensive?
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Why are heavy aero wheels so expensive?
I've been browsing online shops for a new set of wheels and i was surprised to notice that in many cases the expensive high-end deep-section areo (TT or Tri) wheels are actually heavier than the lower cost shallow section road wheels. I guess that this is because there is more material required to produce a deep section.
So am I correct in syaing that what one is actually paying for is aerodynamics, and that the benefit gained from the improved aerodynamics is greater than the extra effort required to push along slightly heavier wheels?
So am I correct in syaing that what one is actually paying for is aerodynamics, and that the benefit gained from the improved aerodynamics is greater than the extra effort required to push along slightly heavier wheels?
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Originally Posted by adholman
So am I correct in syaing that what one is actually paying for is aerodynamics, and that the benefit gained from the improved aerodynamics is greater than the extra effort required to push along slightly heavier wheels?
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Yeah, because once you get those things up to speed, they ain't gonna stop. Kind of like a freight train. You don't need to have a wheel that accelerates well because that is only a very tiny portion of the TT/Tri (like the beginning).
#4
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Originally Posted by Snicklefritz
Yeah, because once you get those things up to speed, they ain't gonna stop. Kind of like a freight train. You don't need to have a wheel that accelerates well because that is only a very tiny portion of the TT/Tri (like the beginning).
"How can it be that wheel inertial forces are nearly insignificant, when the advertisements say that inertia is so important? Quite simply, inertial forces are a function of acceleration. In bike racing this peak acceleration is about .1 to .2 g’s and is generally only seen when beginning from an initial velocity of 0 (see criterium race data in Appendix D )"
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from what i can tell, none of you are right. heavy aero wheels are so expensive because you pay by the pound, kind of like when you go and buy cold cuts at the deli or supermarket.
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Originally Posted by asgelle
Here we go again. Inertia plays virtually no role in road cycling. The third sentence directly contradicts the first two. https://www.biketechreview.com/archive/wheel_theory.htm
)"
)"
I'll say this again: accelerating from very low speeds to very high speeds as quickly as possible is no more important than it is for the world's elite track riders. So, if light wheels are the 'speedy priority' that some ads would have us believe, why then, when these riders can win or lose a medal by 1/100 of a second, do many of them use 2kg wheelsets?
I'll tell ya why, because the fastest wheels (exept when you're riding up very long and steep mountains) are ones that are stiff and aerodynamic
check out the weights of the fastest bikes in the world:
https://www.cyclingnews.com/track/200...k_worlds_bikes
.....over 19lbs for the Dutch pursuit bikes!! And they don't have gears, brakes, etc, etc
and arguably Mavic's fastest road wheel, the Cosimic Carbone SLs, are around 1800g!
https://weightweenies.starbike.com/li...ype=roadwheels
I'd sooner have a pair of Carbones than some floppy, low profile 1400 wheelset, with flimsy DB spokes
Last edited by 531Aussie; 10-19-06 at 11:40 AM.
#8
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Originally Posted by 531Aussie
AGREE AGREE AGREE!!!! Light wheels are the latest marketing hype, along with the feeling that we all must now have a sub 1kg frame. Back in my day, there was never any talk about lightweight parts, it was all about stiffness. In the late 80s, everyone was rushing out to buy heavy Colmbus MAX and EL frames because they were stiffer than 531. I reckon all the weight weeny stuff was started by the triathletes -- they were the first guys I heard
I'll this again: accelerating from very low speeds to very high speeds as quickly as possible is no more important than it is for the world's elite track riders. So, if light wheels are so fast, why then, when these riders can win or lose a medal by 1/100 of a second, do many of them use 2kg wheelsets?
I'll tell ya why, because the fastest wheels (exept when you're riding up very long and steep mountains) are ones that are stiff and aero
and arguably Mavic's fastest road wheel, the Cosimic Carbone SLs, are around 1800g!
https://weightweenies.starbike.com/li...ype=roadwheels
I'd sooner have a pair of Carbones than some floppy, low profile 1400 wheelset, with flimsy DB spokes
I'll this again: accelerating from very low speeds to very high speeds as quickly as possible is no more important than it is for the world's elite track riders. So, if light wheels are so fast, why then, when these riders can win or lose a medal by 1/100 of a second, do many of them use 2kg wheelsets?
I'll tell ya why, because the fastest wheels (exept when you're riding up very long and steep mountains) are ones that are stiff and aero
and arguably Mavic's fastest road wheel, the Cosimic Carbone SLs, are around 1800g!
https://weightweenies.starbike.com/li...ype=roadwheels
I'd sooner have a pair of Carbones than some floppy, low profile 1400 wheelset, with flimsy DB spokes
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Originally Posted by asgelle
Here we go again. Inertia plays virtually no role in road cycling.
I'm not going to let a bike review try to teach me physics.
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Originally Posted by bikerboyd
I'm not going to let a bike review try to teach me physics.
By the way, you might want to check out Kraig Willet's resume before you dismiss his writing as "a bike review".
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Originally Posted by asgelle
Here we go again. Inertia plays virtually no role in road cycling. The third sentence directly contradicts the first two. https://www.biketechreview.com/archive/wheel_theory.htm
"How can it be that wheel inertial forces are nearly insignificant, when the advertisements say that inertia is so important? Quite simply, inertial forces are a function of acceleration. In bike racing this peak acceleration is about .1 to .2 g’s and is generally only seen when beginning from an initial velocity of 0 (see criterium race data in Appendix D )"
"How can it be that wheel inertial forces are nearly insignificant, when the advertisements say that inertia is so important? Quite simply, inertial forces are a function of acceleration. In bike racing this peak acceleration is about .1 to .2 g’s and is generally only seen when beginning from an initial velocity of 0 (see criterium race data in Appendix D )"
Very interesting article, thanks for posting it.
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Aero wheels are heavy because the rims are 2-3 X as deep as regular road rims. More material = more weight and more carbon material = more expensive. Try duplicating a Zipp 808 using all alloy and see where you end up.
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Originally Posted by Enthalpic
Yes.
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Originally Posted by asgelle
Here we go again. Inertia plays virtually no role in road cycling. The third sentence directly contradicts the first two. https://www.biketechreview.com/archive/wheel_theory.htm
"How can it be that wheel inertial forces are nearly insignificant, when the advertisements say that inertia is so important? Quite simply, inertial forces are a function of acceleration. In bike racing this peak acceleration is about .1 to .2 g’s and is generally only seen when beginning from an initial velocity of 0 (see criterium race data in Appendix D )"
"How can it be that wheel inertial forces are nearly insignificant, when the advertisements say that inertia is so important? Quite simply, inertial forces are a function of acceleration. In bike racing this peak acceleration is about .1 to .2 g’s and is generally only seen when beginning from an initial velocity of 0 (see criterium race data in Appendix D )"
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wouldn't a heavier wheel act kind of like a flywheel from an engine. The flywheel stores energy from the engine to keep it turning between the firing of the pistons. I just got into road biking, so I am just guessing here.
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in short: Any energy you put into translating and rotating the wheels you get back, except for the sum of kenetic energy and the difference in potential energy at the finish line compared to the start.
Want to know how much energy goes into spinning your wheels? put your bike in the big ring and the small cog, lift up the rear wheel and push the pedal until it spins at whatever your cruising speed. It's less than what (I hope) you can give with your arm in one stroke.
The angular momentum of the wheels is negligable when calculating power required on a road bike.
Want to know how much energy goes into spinning your wheels? put your bike in the big ring and the small cog, lift up the rear wheel and push the pedal until it spins at whatever your cruising speed. It's less than what (I hope) you can give with your arm in one stroke.
The angular momentum of the wheels is negligable when calculating power required on a road bike.
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Originally Posted by SpotTheCat
The angular momentum of the wheels is negligable when calculating power required on a road bike.
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Originally Posted by soccerun8728
wouldn't a heavier wheel act kind of like a flywheel from an engine. The flywheel stores energy from the engine to keep it turning between the firing of the pistons. I just got into road biking, so I am just guessing here.
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Originally Posted by asgelle
From your post, you obviously didn't read the article which has nothing to do with a review. It does, on the other hand, present the equations of motion for a bicycle (which have been validated numerous times to an accuracy of a couple percent or less), both numerical and empirical data, and results derived from and supported by that data. It really doesn't matter where you learn your physics, but based on your misapplication of F=ma, I'd suggest you learn it somewhere. The key is not that acceleration is 0, but rather that it is so small that any evaluation of equipment will not be affected by it's inclusion.
By the way, you might want to check out Kraig Willet's resume before you dismiss his writing as "a bike review".
By the way, you might want to check out Kraig Willet's resume before you dismiss his writing as "a bike review".
#21
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Originally Posted by SpotTheCat
in short: Any energy you put into translating and rotating the wheels you get back, except for the sum of kenetic energy and the difference in potential energy at the finish line compared to the start.
#22
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Originally Posted by uberclkgtr
Interesting. I imagine if he modelled a commute or perhaps some different types of races, where there are lots of short accelerations, wheel weight might make a bigger contribution to performance.
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Not that I read the review but I spent the summer with a wheel manufacturer having me study this stuff. I don't have a public formal report but wheel innertia is negligable. Additionally, look at what your wheel weighs, look at what you weigh. Now, if you want to talk about motion, look at your legs. It's like the argument that ceramic bearings weigh less ('m not talking about durability, just the innertia claim). The innertia difference between steel and ceramic balls in a bike is the same innertia change as making a pair of cycling socks 0.5mm shorter. Unless you have a huge hill (Read: Alpe d'Huez) it's worth the aero. Adding 10kg to an almost flat course (Read: TT's in this year's tdf)translates while removing 100g of drag actually decreases the time. Anyways, if you want to look at weight, cut that long hail, skip socks, bar tape, and a cup of water... then notice that you aren't any faster but are lots less comfortable.
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Originally Posted by jccaclimber
Not that I read the review but ...
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Originally Posted by 531Aussie
I'll tell ya why, because the fastest wheels (exept when you're riding up very long and steep mountains) are ones that are stiff and aerodynamic