It's all about the resin. Once the resin in the break track hits its glass transition (Tg) temperature, its in trouble.

Different companies address the Tg issue in different ways. Zipp sources their resin from an F1 supplier, aiming to get a resin that withstands more heat, while Reynolds looks at the problem from a different angle, trying to lower the break track tempratures with special pad composites and track treatments. (I'm paraphrasing RBA - they did a great piece this year on carbon clinchers in their 2012 Buyer's Guide...it's worth a read.)

At the end of the day a rim built with inferior resins will have a harder time dealing with heat. And if you ride the wrong pads and ride the breaks, look out.

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Fear is healthy, panic can be deadly

Have to agree with Pez here. Zipp has the best brake tracks going in dry conditions. Enve 3.4, 6.7, and 8.9 takes a slight lead in the wet, I imagine simply due to the rough surface texture. The old Enve rims were highly inconsistent, many had crazy pulsing.

Zipp QC is pretty incredible. In the last few years I've never had one wheel feel any different from any other of the same model. If lots of rain rides are in your future you shouldn't be on any carbon braking surface anyway.

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