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One for the wheelbuilders, I have 20\24h carbon clincher wheels that I'm considering relacing to disc hubs. Just wondering if 20h at the front is really enough for a road disc bike given that I'm not a whippet?
I'd up the spoke count personally, but it does depend on the intended use. If it's just on the road, you'll be fine, just keep an eye on the tension. If it's for 'gravel grinding', you might run into more problems.
You may need a handful of brake on any surface.
Are there 20H fr disc hubs available?
Im not sure I would, definitely not if I was paying for it.
Yeah, you can now get 20\24 disc sets. I really think 24 at the front is a better idea but liked the idea of using an existing set of rims.
If the hub is available and the rim is rated for disc.... What's the problem?
Ah, never considered whether rims were disc rated, back to the drawing board :-\
Rims are/aren't disc rated?
Really?
how deep are the rims? That is the main factor IMO. I wouldn't have any concern riding a 20h disc wheel on the road so long as it was a pretty deep rim - say over 40mm, and not too heavy a rider - say under 90kg. Plus as above the rim should be rated for disc use.
IME some are. With 20h I'd want to know ❗
Rims are/aren't disc rated?
Some rims will specifically say whether they can be used with disc brakes, and some exclude it. If it's got a brake track, it's worth asking the question.
at a guess they will be fine
https://fernandoj.wordpress.com/2013/11/01/a-20-spoke-disc-wheel-for-cyclo-cross/
and Cannondale team used 24/24 on Zipp 303's in 2013 (SRAM Rise 24h Hubs)
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DT Swiss do a 20 hole front 350 road disc hub. Centrelock only through.
They are Light Bicycle 35mm deep rims, which are likely disc rated as you can spec them without brake track. However, I think I will just get some new alloy rims as at 85kg, I'm not convinced low spoke count is the best idea.
And the logic to rting a rim for disc use is pulling spokes through the rim? Or what?
I've used all sorts of rims with discs, never even considered it.
I could be interested in the LB rims if they're available?
Should be fine, laced 2 cross. I'd recommend some stronger spokes - not Revolutions! Perhaps a build with CXRays from a reputable builder.
And the logic to rting a rim for disc use is pulling spokes through the rim? Or what?
Yes, exactly, I have had some lightweight Reynolds rims crack at the spoke hole and the explanation given was that it was because it was used with a disc hub. This was quite some time ago though I have to admit - i.e. before discs were becoming in any way common on road bikes. The fact they were being used as mtb wheels probably didn't help...
If it helps I've built the same LB rims on DT disc hubs and they've been fine for the last 6 months of commuting (34 miles a day). That is 20 hole using DT Revs too.