Originally Posted by
terrymorse
Personal data point:
I have been using a single pair of carbon wheels with rim brakes since 2011. I often descend mountain roads that require aggressive braking.
I have never once experienced overheated rims or tire blow offs, and the braking surface of the rim shows very little wear.
Then again, I know how to brake correctly. It's not that difficult.
this is a pretty unhelpful comment. Not only is it condescending, it doesn't contain any information we can use. If you've never encountered even an ounce of brake fade on carbon rims, you're not actually doing very sketchy descents.
To OP, aluminum is safer than carbon, simple. If you're really afraid of overheating your rims, the peace of mind with alloy is worth it. Not that alloy rims won't fade at all. It's just nearly impossible to have the rim itself fail from heat.
tubes vs tubeless: definitely avoid latex tubes with rim brakes. However, I've personally never heard of a butyl tube failing from braking. Plus, a tube is more likely to handle overpressure from heat than a tubeless setup. That being said, I think it's really not worth choosing one over the other for this reason. Other things, like ease of setup or flat prevention are much better reasons.
EDIT: I should say that I've been using carbon rims for the last 3 years in the hills of california. Most descents are ez, no stress whatsoever. Some, like mt. Umunhum or metcalf road (sustained -10%, hard turns) require me to be very mindful about how I brake. But I'm a very confident descender, and I still face a good deal of brake fade. I'm probably not really close to my rims exploding, but it's unpleasant. I have yet to attempt quimby road on these wheels for that reason (bumpy, technical, -13% for a mile).