On Sunday, December 16, 2018 at 7:19:46 AM UTC-8, sms wrote:
On 12/16/2018 12:21 AM, wrote:

Are you saying that full CF rims brake as good as AL rims and don't get worse when it is wet? That is not my experience owning a set of Zipp wheels and Mavic Comete wheels. At best they brake half as good when dry and even worse when wet. I think I'm not the only one with that experience. I don't dare myself in the mountains with a full CF front wheel. They are aero wheels and I use them as such in time trials and trying to go fast on the flats. Thank god we have a lot of that here ;-)

It's not just braking ability, it's heat dissipation. The CF rims are
not going to last as long as aluminum rims mechanically, but they also
can fail more spectacularly due to heat. One CF rim brand did an
extensive test of the heat dissipation capability of different rims to
showcase their proprietary resin.
https://www.bikeradar.com/road/gear/article/alto-destroys-carbon-clinchers-in-braking-heat-test-51474/

"The issue with carbon clinchers is that rim braking generates heat,
and, when pushed to extremes, can cause the resin to soften, which can
lead to the rim bubbling or folding open. In worst-case scenarios, the
rim can fail enough that the tire can come off or the inner tube can
burst from the heat. Years ago, a few events like Levi's Gran Fondo in
California banned carbon clinchers after multiple incidents on steep,
winding descents. "

Carbon Fiber has a lower heat capacity than aluminum. But I have heated aluminum rims up to the point where you cannot touch them on hard descents and I have never gotten CF rims more than hot to the touch and not capable of burning you like aluminum rims.

I have also heated aluminum rims so hot that they caused a flat by burning through the cord of the tire. I haven't enough experience with CF yet but they are so much stiffer on descents and hard turns that I think that the only time I would need to brake like that would be from coming upon an accident on a blind turn.