Aero Wheels! 38mm or 50mm?

[oneironman]

I have the opportunity to pick up a sweet set of carbon wheels. I cannot decide what to do? I love the weight of the 38mm (1181g), but I like the depth of a 50mm (1340g). The 38s might be more pleasing on my frame look-wise since it is a 50cm and the weight would bring my Cannondale down to 14.25lbs (With my new brakes and saddle I will be sub 14! Yeah!) Once said and done, I will post pics.

Here's the question, will I be losing much in the department of aerodynamics on rolling and flat roads?

I knew this was the place to go since I am a fellow weenie!

Thanks for any advice or data!

Sorry-forgot to mention the wheels will be used mostly for road races, crits and some fast group rides.

[bcheung]

50mm gets my vote.

[racermech]

50cm frame means you are a pretty small person, I would guess pretty light also. The 50mm could prove to be a bit much to handle in any sort of cross winds. I am 5'10 around 150-155lbs and sometimes my 404's can be a bit much in a good gust.

Are these for daily wheels, or race day only?

[dgasmd]

Assuming you are not doing time trials or racing, which for what you said I can't tell either way, I would go for the 38 actually. Maybe be ignorance or lack of ability, but I've had both and go at the same speed with either one. I ride alone mostly. I did not notice any wind/handling issues until I went with much deeper wheels than 50 mm, and I live in a pretty windy place.

[mazdatech10]

I'am 5'8" and ride a 50 cm cannondale also and have dv46 and some 50mm carbon wheels on it and 46 and 50 's can be a handful on a windy day. even with my 25's i have some problems because of the big tubes of a system six

[mr_tim]

You didn't say how much you were spending (assuming your buying, not sponsored...?)

If your careful on your budget / selection, you could have both 38 & 50mm sets.. you can do things differently by selecting carefully & not just picking the factory wheels with the nice stickers

FWIW I would go with 38mm set if I could only take one wheel to a race / crit. They seem more manageable & therefore use-able in more conditions, therefore more bang for buck in the long run.

Lastly - As is often said about wheel choices for crits etc - if your in a group orientated race rather than break away epics, then often the aero benefits are negated by the fact you can suck peoples wheels & hide out of the wind for a lot of the time.. therefore a smarter choice could be low profile carbon rim to get the weight as low as possible, so you have the easiest possible time on bringing speed back up out of corners. No problems with wind + lightest choice.

[nitropowered]

Buy a set of 50mm and a 38mm front wheel.

Ride 50mm on calm days and swap in the 38 if it is too windy

[Perfition]

50 mm. will be far easy to handle... I'm 65 kg. and i handle Zipp 404's with no probs

[lancejohnson]

What are the wheels? The difference in rim shape will have a lot to do with it. If the shape on the 38 is good the the difference to the 50 with a less good shape will be nil or negligable. If the shapes are similar then it will probably be a small and fairly linear advantage.

[Biplrsaba]

I have 52 now and am looking real hard for 38 for everyday. A good crosswind on most days riding solo or in a group adds that extra energy expenditure to fight the wind I just don't need. I love having deep hoops and they have a place just IMHO not an every day wheel

[c50jim]

Interesting thread. I thought most people here would say you should go with 50. I'd say that it depends a little bit on the conditions you'll usually encounter. If it tends to be gusty, even 38 may be a handful at times. If it's pretty calm, you may be OK with 50. Since you talk about road races, crits ( do you really want to use expensive wheels in crits) and fast group rides, and not TTs, I'd suggest the 38s since you might appreciate the acceleration of lighter wheels more than a small aero advantage. Also, as Lance Johnson said, shape is important since carbon rims aren't all that same in terms of aero benefit at the same depth.

[nelnel129]

I would like to have a set of 38mm wheel. Any suggestion for it?
I found 2 different band have product 38 profile only (FFWD and Easton)

[2002SaecoReplica]

Get the 50mm.

The aero will outweight the weight you might save. I'm sure the 50mm rim will be stiffer too. I had issues with my AC38's not being stiff enough when I went to stomp on them. They had the cx-ray spoke upgrade and were under 1100 grams so they were super light but I could feel them flex in a sprint or in a hard corner of a crit.

[Skoobi]

I'm still on my ongoing (4yrs now) project of lightening my r3. Finally had the chance to get carbon deep sections and was about to get the dv46ul for a good balance of weight and aerodynamics. But when I saw the sdv66c. I couldn't resist them!
So I broke the rules of weight weenism but just couldn't resist them.

Have not regretted so far and could definitely recommend going for the deepest wheelset which suits your application. Ie. Clincher, crits, etc.

For info I'm 72 kg and mostly ride alone and the occasional fast group ride.

[HakanC]

What are the wheels? The difference in rim shape will have a lot to do with it. If the shape on the 38 is good the the difference to the 50 with a less good shape will be nil or negligable. If the shapes are similar then it will probably be a small and fairly linear advantage.

I agree with this, as do windtunnel testing of aero wheels


But the most important factor is the rim shape of the different wheels.