Looking for Shallow Carbon Rim
03-30-23, 05:56 PM
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Looking for Shallow Carbon Rim
I'm looking to build up a front wheel for windy-day rides. The primary criteria is to be least affected by cross winds. So, essentially the shallowest rim I can get. I have experience with an alloy rim that I like, Bontrager Paradigm that looks to be 18 mm deep. And this is likely what I will end up buying. But, if I can get a carbon rim that is significant lighter, I would use that. But so far, I'm not finding any really shallow carbon rims. Best I have found is 25 mm deep. though I have dismissed, out of hand, the really expensive rims >$400.
So, I thought I'd ask here if someone has a suggestion for a shallow <20 mm deep carbon rim.
Of course, susceptibility to cross winds is not just about rim depth, the way it handles airflow (stalling) is a factor. This is one reason I like the Bontrager rim mentioned, it has a nice aero-like profile, so I believe it is likely as good as any shallow rim as far as air flow is concerned. It's just it is heavier than a carbon rim would be by probably something like 150-200 g. The extra weight is not a big deal, but lighter is better than not.
So, I thought I'd ask here if someone has a suggestion for a shallow <20 mm deep carbon rim.
Of course, susceptibility to cross winds is not just about rim depth, the way it handles airflow (stalling) is a factor. This is one reason I like the Bontrager rim mentioned, it has a nice aero-like profile, so I believe it is likely as good as any shallow rim as far as air flow is concerned. It's just it is heavier than a carbon rim would be by probably something like 150-200 g. The extra weight is not a big deal, but lighter is better than not.
03-30-23, 06:23 PM
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Light Bicycle is the 25 mm rim I mentioned. And I've used their rims on several builds. But I'm looking for shallower than 20 mm. Again, crosswind performance is the main criteria, weight is secondary, but that's why I'm asking.
03-30-23, 06:47 PM
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Get a Mavic GL380 off eBay. They’re aluminum tubulars and have been off the market for eons but still pop up. Flatter than an open pro and I had a pair of sun 1200gm wheels with these back in the rim brake era.
03-31-23, 12:46 AM
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I can't imagine 25mm being affected by crosswinds to any noticeable degree. My 32mm rims are because I found the 56mm ones to be too unstable and they feel like any other shallow rim I've ever ridden.
If you decide 25mm is close enough, this is a heck of a deal, and they have it in 20, 24, 28, and 32 hole at the moment. *edit: these are for disc brakes. Not sure what you're after.
https://www.randombikeparts.com/prod...48740c9f&_ss=r
If you decide 25mm is close enough, this is a heck of a deal, and they have it in 20, 24, 28, and 32 hole at the moment. *edit: these are for disc brakes. Not sure what you're after.
https://www.randombikeparts.com/prod...48740c9f&_ss=r
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03-31-23, 01:49 AM
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My old tubular racing wheels have a total 30.6 mm profile, that is tire plus rim, with a nominal 25 mm Continental Giro mounted, for an actual width of 22.5 mm on Scheeren Weltmeister aluminum rims. They were designed for a time when stages were not cancelled for crosswinds. Those particular rims have wood inserts at each spoke to distribute the stress, and were also unusually light. Subtraction would suggest an effective rim depth (in the middle) of about 8 mm. Visually, the apparent rim depth is about 10 or 11 mm. I didn't see any shallow carbon tubular rims in the first two pages of of an ebay search - shallowest were 25 mm depth.
My theory is that the little crevice between the tubular rim and tire acts like the dimples on a golf ball, lessening the air resistance for greater speed.
You could find out, if you're tubular-curious...
C'mon - it's only one wheel!
My theory is that the little crevice between the tubular rim and tire acts like the dimples on a golf ball, lessening the air resistance for greater speed.
You could find out, if you're tubular-curious...
C'mon - it's only one wheel!
04-02-23, 05:39 PM
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I can't imagine 25mm being affected by crosswinds to any noticeable degree. My 32mm rims are because I found the 56mm ones to be too unstable and they feel like any other shallow rim I've ever ridden.
If you decide 25mm is close enough, this is a heck of a deal, and they have it in 20, 24, 28, and 32 hole at the moment. *edit: these are for disc brakes. Not sure what you're after.
https://www.randombikeparts.com/prod...48740c9f&_ss=r
If you decide 25mm is close enough, this is a heck of a deal, and they have it in 20, 24, 28, and 32 hole at the moment. *edit: these are for disc brakes. Not sure what you're after.
https://www.randombikeparts.com/prod...48740c9f&_ss=r
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04-03-23, 08:26 AM
#9
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I found 45mm rims to be dicey on a windy mountain descent, so my latest two wheel sets have BTLOS 29mm deep rims. I doubt that shallower rims will make a significant difference.
https://btlos.com/ar-clincher-hook-l...arbon-wheelset
https://btlos.com/ar-clincher-hook-l...arbon-wheelset
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04-03-23, 09:51 AM
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I found 45mm rims to be dicey on a windy mountain descent, so my latest two wheel sets have BTLOS 29mm deep rims. I doubt that shallower rims will make a significant difference.
https://btlos.com/ar-clincher-hook-l...arbon-wheelset
https://btlos.com/ar-clincher-hook-l...arbon-wheelset
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04-03-23, 10:00 AM
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04-04-23, 11:31 AM
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Till a week ago, I would have generally said that stay under 35 for sure but my new ZIPP 303 Firecrests are as unaffected as my 30mm shadow alloy Easton R90 SLs. I'm 175 lbs and have ridden in some seriously windy Springs here. The ENVE Foundation 45s are not as stable. I am still a bit surprised and am thinking of using a second set of ZIPP 303 Firecrests on my gravel bike. I'm in Colorado. In general though, under 30 is perfect. My DT 411s were around 21mm in height and unaffected by wind plus very comfy!!
