Aero vs light wheels

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YoKaiser
Posts: 129
Joined: Thu Aug 20, 2009 8:02 pm

by YoKaiser

Whats the consensus or aero vs light? Has wheel weight reached a tipping point whereby adding a few grams for improved aerodynamics is acceptable? Specifically on weight weenies why are people choosing a 50mm 1200odd gram wheelset over a 1000odd gram 20mm one?

BmanX
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by BmanX

I think there is a point where you have to weigh (pun intended) both and try to find the best balance if possible. For me this is what I have tried to do on my SLC. I wanted a nice light aero build. Aero trumps weight but if you can have a 13 lbs fairly aero bike over a 18 lbs fairly aero bike, I will take the one that is 5 lbs lighter. No with that said, I think the weight penalty for having a very aero wheel when racing is a must. Zipp, Enve and Hed seem to be the only way to go.
BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5960g/13.13 lbs

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djconnel
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by djconnel

It depends on the terrain and what your goals are, of course. This is weight weeenies, not race weenies, so people here tend to focus on climbing steep hills.

BmanX
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by BmanX

People are looking for any advantage they can get whether it is a lower weight or more aero. So why not go after both and get as much savings as possible. I think they can both exist together but people tend to be of one side or the other.

I would love to start a small following of people that believe both are important and can live together happily.

I would love to have a road bike where you build in the new TRP aero brakes into the forks and rear chain stays, internal Di2 with internal battery and all cables hidden as much as possible. This would create an amazingly clean road bike that could be light and aero.

Not hard to do but just hard getting someone to build it.
BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5960g/13.13 lbs

voodoojar
Posts: 659
Joined: Sat Mar 19, 2011 10:50 pm

by voodoojar

Sure you can buy an aero frame, aero brake and aero wheels but how exactly they work together is as mysterious as sorcery to me. So until I get a wind tunnel in my garage and learn how to use it I really cant comment on exactly how aero a build is. Weight is easier to figure out.

dcl10
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Joined: Mon Oct 25, 2010 6:51 pm

by dcl10

I've tried both extremes, and I find that a compromise between the two is what works best for a general purpose race bike. I know a lot of sponsor team liaisons and engineers will tell you aero trumps all, and if you look at the math it makes sense, but that does not always correspond to real world experiences. For instance when climbing, yes a 404 is likely faster than a 202 if you do the math, but that math does not account for the muscle fatigue you'll experience by constantly having to re-accelerate a significantly heavier rim. Nor does it take into account the mental effect of having a more or less responsive bike. Not to mention a lighter rim will allow you a smoother pedal stroke, which is more efficient as well. So there is a reason why a lot of pro's ignore the engineers in such situations. It's not that the math is wrong per se, it's that it does not take into account all the more complex variables that are not so easy to put numbers to.

naisan
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by naisan

Aero.

Phill P
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by Phill P

When you look at where *most* people ride, there are flatter sections between the hills, and the climbing km's only equate to a smaller % of overall rides.
You look at most pro races, there are looong flatter sections before the hills.
In these cases a lighter weight aero build is the way to go.

If you live on flat plans and an over pass bridge is the closest you get to a hill, then aero all the way!

If where you ride the only flat sections are the crest of a hill or the bottom of a valley just before the next hill, then you clearly want a bike biased towards climbing and descending. That will likely mean a lower profile rim, and more spokes. Any aero benefit will just mean a higher possible critical velocity coming back down.

If you are a smaller rider the power to weight ratio is more important for climbing, you'll be more aero just by being smaller. Plus you'll get pushed around more by deep rims in cross winds and waste a lot of energy.
If you are a big rider an extra 500grams will matter less to you, and you want to get the most out of your horse power on the flats.

Its all horses for courses. Depends on the terrain of where you ride, and your riding style.

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Juanmoretime
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by Juanmoretime

I love my light road bike. When I look at what I go the fastest on its by a huge margin the heavier with heavy wheels tt bike. That disc and trispoke upfront sport some serious weight!
RESIDENT GRUMPY OLD MAN.

sedluk
Posts: 409
Joined: Mon Sep 07, 2009 3:10 am

by sedluk

If you ride with other riders, then the most important factor is, when are you getting dropped? It has nothing to do with the mathematics of percentage hills/flats or wind tunnels. If you are getting dropped, you will spent exponentially more energy than a heavier bike or an aero bike.

So if you are getting dropped on the flats, you need more aero. If you are getting dropped on the hills, you need less weight.

To the extent that you can get aero with low weight, it will help you conserve energy and allow you not to get dropped on the hills.

I love to ride with guys with heavy aero bikes. I really enjoy dropping them on the first hill. Then they can use all that aero to try to catch the front group that contains the strongest riders.

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LouisN
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Location: Canada

by LouisN

sedluk wrote:If you ride with other riders, then the most important factor is, when are you getting dropped?
So if you are getting dropped on the flats, you need more aero. If you are getting dropped on the hills, you need less weight.

Damn!!! All these years I though it was because of a poor engine !!!
Thanks for enlighting me :thumbup:

Louis :)

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HammerTime2
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Location: Wherever there's a mountain beckoning to be climbed

by HammerTime2

sedluk wrote:If you are getting dropped on the hills, you need less weight.
Hahh, not necessarily. I know one guy, heh, heh, who most frequently got dropped in the hills ... going down.

BmanX
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Joined: Thu Nov 10, 2005 5:31 pm

by BmanX

I think we need to clarify what someone would call an aero bike and the weight that goes with that and what a light bike is. I do not see why you can not have both.

A 900g aero frame will be faster than a 900g non aero frame.

A 1100g aero wheelset will be faster than a 1100g non aero wheelset.

So why would you not go aero and light?

With the 6.8 so easy to get to, why would you not design a super aero light bike to race.

If you can use less watts to go faster and further, why not.
BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5960g/13.13 lbs

fdegrove
Tubbie Guru
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Location: Belgium

by fdegrove

Hi,

With the 6.8 so easy to get to, why would you not design a super aero light bike to race.


Sure but the light part of the equation is always going to be limited by that silly 6.8kg barrier.
Within that envelope you can strive for least rolling resistance of your footwear and the most ergonomic/ aero compromise on the bike too.
Either way, under most circumstances aero more often than not trumps weight.

Ciao ;)
Being a snob is an expensive hobby.

woodys737
Posts: 27
Joined: Fri Oct 13, 2006 3:00 am

by woodys737

Hate to admit it but, I sold the 24mm 1175g set for a 50mm 1260g set just for aesthetic reasons. Consensus? :noidea:

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