I installed Kettle Cycle’s SFL SiCCC carbon-fiber rotors on my cross bike yesterday, or actually I should say my bike shop installed them because I don’t have a torque wrench. I was among the first to get them because I supported their Kickstarter.
As I was leaving the bike shop, I tried to brake and found that they had little or no braking power. I rode to the gas station next door and followed the bedding-in procedure in their parking lot, which is basically just accelerating to jogging speed and braking to a stop 10-15 times. After that they seemed to brake as well as the stock steel rotors I had on previously.
I didn’t buy these to be a weight weenie, even though they are very substantially lighter than the rotors I had on there before. I bought them because I hoped that they would solve the screeching brake problem I was having with the stock steel rotors, particularly when they got wet. It was raining heavily on the way home from the shop, and I’m happy to say that there wasn’t even a trace of screeching. Instead, there is sort of a quiet sanding noise that you can only hear if you’re really listening to it. It does make me question what is happening to my brake pads, though. The braking was fine even on 12% to 15% descents.
I don’t know how long they will last, of course, but after two days of riding and about 50 miles, I’m pleased. Let me repeat this, though, in case it wasn’t clear: you must follow the bedding in procedure or you will die. It’s simple: accelerate to maybe 10 mph, then slow down. Repeat 10-15 times somewhere where you won’t crash into something. You’ll notice the braking power become considerably better from the beginning to the end of this process. Once you’re done, you get about 80% of the braking power you’ll get with a steel rotor. After another 10 or 20 normal brakes and you won’t be able to tell the difference. I don’t know if that is because the rotors are approaching the braking power of steel rotors or if I just adapted. But the end result is the same.
Addendum: I am using Swiss Stop pads, and I installed a fresh set when switching rotors.