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Aerodynamics or Weight for Wheelsets?(5 posts)

Aerodynamics or Weight for Wheelsets?Eepee Ohh
Feb 8, 2002 5:16 PM
The question of the decade: is aerodynamics or weight more important in wheelsets? Here's what I came up with: in racing, aerodynamics is far more important that weight, at least in the overall system (bike + rider). Anyone who disagrees can draft a truck and realize how much of cycling is air resistance. With that in mind, it seems like the majority of the air resistance comes not from the wheels, or even the bike, but from the rider's position. So, I'm not sure how much air resistance can be attributed to wheels.
On that note, weight can also become important, not so much for climbing (though that's important too), but for acceleration and handling. Now, rotating rate is certainly not everything but is pretty damn important in acceleration, so a light rim (and a light bike too) seem important for acceleration and maneuverabilty. Afterall, the physics equation for work is mass*displacement, so logic stands that lighter wheels are easier to accelerate. So, that too seems important.
But wait... what about kinetic energy? Although lighter wheels may be easier to accelerate, it also stands reason that they take more energy to hold at speed. Once you get a nice heavy set of aero wheels going the certainly keep going well, and to an extent the "flywheel" effect can be nice... at least until the sprint.
So, what is the correct answer? From my ponderings, I have decided that it mainly depends on what type of racing you do. For flat time trials, it seems like a not-very-light but aero wheel is good (hence disk wheels), for climbing and sprinting, light-rimmed wheels are good, and for road racing something in between is good. So, that puts us firmly back with what is already known. But... what do the aspiring amateurs with enough money for only one set of NICE racewheels do? A nice, light set of wheels would be fun for crits, but come the time trials or long solo road breaks, you would be cursing the day you built a 32 spoke wheel. A deep section, moderate weight wheel like a Carbone or HED could be fun on the TT's and the breaks, but in that final sprint up Alpe du Huez you might be feeling a little lethargic with all that extra rim blubber.
With all this in mind, it seems to me that perhaps the best thing to do is get a nice set of carbon deep-section wheels and swap tires for different events. For example, something like a ZIPP 404 (or even 303) with some light tires on it would be plenty light for crits and climbs, but if you throw on a fat TUFO tubular-clincher for TT's and road races you would have a nice, stable, flywheel-like ride and plenty of security.
So there you go... those are all the ramblings I've been able to come up with, and of course, keep in mind that I am talking about racing, so please don't say "for most people, aerodynamics doesn't matter..." Good stuff... eager to hear what people have to say.
re: No one answer...Akirasho
Feb 9, 2002 6:23 AM
Not really the question of the decade. I think most of us realize... you need the right tool(s) for the job...

As you've alluded to, there are other variables that come into the equation.

The question then becomes... what do I go for for a specific race, terrain and conditions... given MY strengths and weaknesses... and that's a question for a lifetime...

We abide.

Remain In Light.
re: Aerodynamics or Weight for Wheelsets?R-I-D-E
Feb 9, 2002 10:13 PM
I have just finished up ordering my new bike and had a similar problem to deal with. Wheels. In the end, I decided that the best possible choice for me would be the new Zipp 303 clinchers.

Tubs are not an option, but I did want a light climbing wheel. Being a somewhat lighter rider (160 lbs), I have a bit of trouble in headwinds. Sooo....enter the 303s. Light, strong, aero....perfect.

Now I wish that they would hurry up and get here!

Ride
from what I readcyclopathic
Feb 10, 2002 5:33 AM
I came to conclusion that aerodynamics outweighs weight by big margin. But I don't do C-races, my main interest is ultramarathon riding, no sprints.

Quite common you ride self-supported, no drafting, so saving 100g on light rim which probably won't take as much abuse is a mood point for me.

Here a few facts:
- in TT wheel aerodrag diff btw good aero and standard 2-3%
- aerodrag changes very little from speed (most of it caused by turbulence)
not another one of these, oh no!!!Woof the dog
Feb 10, 2002 7:24 PM
lol

from what i've read and had a limited experience with, I'd say that you really benefit from light wheels in criteriums and wall climbing ;-) Everywhere else, aerodynamics are more important, especially in individual time trials. Also keep in mind other factors, like rim depth - will a 5mm taller rim make a significant difference? Also, don't forget about crosswinds, as a deep rimed wheel will be a real pain. Then we can get into an argument about tires and rolling resistance in which I get to rub it in everyone's face that thinner tires are indeed faster due to a more aerodynamic profile. For hilly road races, I'd go with lighter wheels as I suck wheel anyway, and its the uphill surges that get you.

You can have both - aerodynamics and light weight - but some drawbacks may be: gluing tubies, spending lots of money, and sometimes durability issues. You can never have it all, seems like.

Damn, I think threads like these come up so often that I will have to keep a list of urls.

Sincerely

Woof, the Coca-Cola enjoying dog.

P.S. Coke or Sprite?