jnbrown

I have always ridden alloy wheels and build all of my own wheels.
My current wheelset uses Reynolds R90 SL and I like them a lot.
I have avoided carbon wheels because of the cost and possible reliability problems.
But both of those things have improved and I now have the means to build some.
I don't race and I am primarily interested in light weight. I realize most people buy carbon wheels for the aero benefits and go with 40mm or greater wheel depth.
I am trying to decide between a depth of 30mm or 35mm rims.
I get the impression from reading other peoples experience that deeper carbon rims can be hard to handle in cross winds and can also give a stiffer harsher ride.
At the same time I have read carbon wheels can actually be more comfortable than alloy so there seems to be a contradiction there.
I am leaning towards 30mm because of the lighter weight and possibly more comfortable ride. 35mm would have the benefit of being a little bit more aero.
Thanks for any advise.

Badger6

The “deeper" the rim, the more it’s going to deflect in the wind. 35mm won't be terribly wild, though.

biker128pedal

I’ve got two sets of Bontrager Carbon wheels (Pro 5 and Pro 51). They’ve stayed true and I’ve not broken a spoke. Unlike aluminum rims over the years. I weight 210 pounds. So I don’t see em being less reliable.

urbanknight

I actually just built up a set of carbon wheels myself. The reason was because I originally bought a set of 56mm wheels and didn't like how they felt in even mild wind. I didn't feel like I was going to crash or anything, but the required manhandling was ruining my zen on twisty descents and that's more important as a recreational rider than shaving off a tiny amount of time.

Anyway, I ended up going with 32mm rims, but only because I found a bargain that I couldn't find on anything else around 35-40. I doubt you'll even notice the cross winds on anything from 30-35.

As for the harsher ride, I really can't notice any difference and figure tire size/pressure/model makes much more of a difference there.

tempocyclist

Tyre and pressure choice will have a far greater effect on comfort than the rims. I doubt you'd notice any comfort differences between a 30 and a 35mm carbon rim either.

If you've got the choice between 30 and 35, got for the slightly deeper 35mm rims. They'll make great all-rounders and arguably have a slight aero advantage.

cxwrench

Don't even let that thought into your head. There is ZERO difference in ride quality between any carbon rims much less any alloy rims. With properly built wheels you'll never be able to feel a difference in 'ride quality'. Unless your tires are concrete or steel. Not a chance.

Russ Roth

With 35mm rims I wouldn't worry much about crosswinds, my 12yo 96lb daughter is riding 35mm carbon rims. Even riding from Jones beach to Captree, which follows the Atlantic coast with the ocean regularly in sight, she hasn't had an issue with crosswinds. Hers can't take narrower than a 25c so I'm not certain comfort is a real issue.

cxwrench

It could be if you over inflated the 25mm tires.

thin_concrete

I have 44s on both of my bikes and love them. I had considered going to 60s for my “daily” but thought that would be overkill for that bike. I bought the other bike with 44s and have found no reason to change them out as that bike sees less use. On my old P3 I ran 45s. The wind off the New England coast can get brutal at times and I have never felt unsteady with my wheels in the 44-45 range. 30s should be no problem at all.

Branko D

I've got two sets of 45mm deep wheels and crosswinds aren't a big deal (72kg guy, so not very light, but not too heavy either) with either. The Mavic SLR 45s is slightly better than the LB R45 rims are but not by much. I mean, it happens sometimes that it "snatches" on a gust of wind when it's really strong but normally it's fine even when it's really windy.

Considering getting a 65mm set, which probably would be a bit much for everyday use, but would be something to bring out on races when it's nice and sunny.

roadie276

FWIW I went from super shallow Dura Ace C24 rim brake wheels (24mm depth at most...may be like 22mm front and 24mm rear) to much deeper Bontrager Aeolus RSL 51's (51mm front/rear). I was also pretty concerned about handling in windy conditions as well, as it's almost always somewhat windy in my next of the woods (New England area), and contemplated going deeper in the rear and shallower in the front if things seemed a bit too squirrely, as I really wanted wheels I could ride every day. It's not apples to apples since I'm on a new bike ('13 Madone to '22 Madone with the new wheels), but I found the deeper wheels to be basically completely fine. I can feel the wind on the windy days, but it's like very minor corrections to keep things headed straight, and I've never suddenly found myself going off in the wrong direction or felt out of control or anything. I think the scariest thing that's happened was that one time a massive gust of wind came directly from the side and moved me over like a foot or something, and that was easy to correct and not really even particularly perturbing. I think the newer generation aero wheels are far superior to old ones. I'm kind of medium weight (75kg-ish), so not sure how much things vary for lighter folks, but I decided to keep the deep wheel on the front and have ridden half a season on them and they've basically been great.

They're not a wonderful value, but check out the Bontrager Aeolus RSL 37's if you want light weight, semi-aero carbon fiber wheels.

SoSmellyAir

I went from 25 mm tires on 17C alloy wheels (Mavic Ksyrium Elite) to 19C CF wheels (FFWD F4R), which slightly improved comfort, most likely due to the increased wheel width, the resulting increased tire volume and decreased air pressure.

The rim height increased from 24 mm front and 26 mm rear to 45 mm front and rear, but I have not noticed any adverse handling in the wind (so far). This will be my first winter (if there is such a season in southern California) riding these new wheels.

procrit

The profiles of the newer deep section carbon rims deal with crosswinds much better than the old deep section wheels from 10+ years ago. You can easily run a 40-50mm carbon rim these days without any fear of being blown off the road. Couple that with wide internal rim width, 28c-30c tires at low pressure, and your ride quality will be awesome.

GhostRider62

Stability in the wind varies a lot depending on how fast you ride and the shape of the wide rim. I have had three sets of 60mm wheels. Two are fine in the wind and the third is a handful at the transition. The difference from most 30-40mm rims to 60mm rims is only 3-7 watts at 30 km/h. There is no harshness difference from 60 to 30mm carbon or to aluminum for that matter.....tire and tire pressures is what controls that.

Carbon rims often have a very wide internal width compared to aluminum rims (say 25mm vs 15-17mm), this "plumps" up the contact patch of the tire and the ride is "smoother".....that might be the increased comfort of carbon of which you are told.

jnbrown

Thanks for that info. Since the saving in watts is quite low that is why I am not wanting to have a deep rim. The 30mm rim saves 30g per wheel over the 35mm. I realize that is not very significant but since weight savings is my primary goal I am still thinking I should go with 30mm.