Lina wrote: ↑
Thu Oct 28, 2021 8:06 am
Going from 20 C to 80 C gives ~1 bar pressure swing at road temperatures which does have an impact on riding quality. And you run into heat problems with inner tubes.
I think you'd be hard-pressed to verify that the average air temp inside a bicycle tire varies by that much, even after intense braking. As was mentioned in another post above, actual pressure measurements show variations quite a bit smaller than that. If that that temp data exists, I'd love to see it.
Lina wrote: ↑
Wed Oct 27, 2021 11:59 pm
Surely not having to have a braking surface on the rim allows for better aerodynamics where the tire meets the rim. Not sure if that's enough to counteract the additional spokes though. Also we do have plenty of examples from early carbon frames why bonding aluminium and carbon isn't probably the best idea.
That's been often asserted/speculated...and yet, I haven't seen any examples of this, or actual data, and wheel rim manufacturers have had plenty of time to make those changes. Then again, if one realizes that prior to the common use of disc brakes on road bikes, aero rim designers basically "ignored" the fact that braking was taking place on the brake track area in regards to shape, then it makes sense why that hasn't come to fruition. I can point to plenty of examples of aero wheels that had aero shaped brake tracks, and not the assumed "parallel" configuration. This was even done on some lower profile aluminum rims, such as the old Zipp 101s.
Also, an aluminum insert, such as a threaded BB shell in a carbon frame, is quite a different use case than a (mostly) non-structural carbon "cap" bonded to an aluminum rim...and I don't recall any large issues with the Hed Jet wheels in that regard, which have been in production/use for quite a LONG time.