sdcoffeeroaster
Active member
I have this posted in the Specialized section but thought I would add a link here. I know that SRAM brakes have a bit of a bad rep with many of us and I can't say I love the use of DOT fluid or the involved bleeding procedure. But I've come to learn to be better at it and I currently don't want to gut my entire braking system which is currently Code RSC 200mm brakes front and back. What I've found is that I really do like the modulation of these SRAM brakes and the RSC version of the Code brakes has a grab point adjustment that really works. My 2021-2 Levo SL expert carbon came with the R version of the Code brakes and a very good friend gifted me the RSC set.
But I've been plagued by lots of squealing from time to time out on the trail even in dry conditions, which I hate. It's sort of unpredictable but seems to be temperature related with it happening more when the rotors are cool not warmed up from braking. Just the act of cleaning a rotor with a cloth can induce some resonance much like a tuning fork. Something I never really experiences with my Focus Jam2 that had Shimano MT520 brakes and rt66 rotors. After many tries at freeing up pistons and bleeding I finally decided to try a set of Shimano RT66 203mm rotors using a 1.5mm shim on the back and the Shimano 203mm mount on the front of my Lyrik Ulitimate fork. Noise gone!!! But I've noticed another issue and that is I happen to have Shimano rotors from two different countries that are wearing differently. The front is Japan, purchased with factory packaging from Jenson and the back is from China, purchased from Commencal and inexpensive when I could not find any of these available anywhere. The Commencal part came in OEM packaging and not the std Shimano box.
You can see from the photos that the back brake from China has very obvious spots that don't contact the pads and this is distortion from the punching process used in manufacture this part. I have heard that Shimano has moved the manufacturing of this rt66 rotor and other low cost rotors to China. So it's likely that future boxed versions of this will also come from China and may suffer from this manufacturing defect as well. For that reason I'm currently waiting for the rt76 to come back in stock. Everyone seems to be out of many 203mm rotors. For now the brakes function and are quiet. I doubt that the back brake has optimal stopping power but I intend to just use it for now until I wear it out. I've emailed Commencal about this. Their rotor only cost $28. compared $47. at Jenson (but none in stock) so it's a case of getting what you pay for I guess.
But I've been plagued by lots of squealing from time to time out on the trail even in dry conditions, which I hate. It's sort of unpredictable but seems to be temperature related with it happening more when the rotors are cool not warmed up from braking. Just the act of cleaning a rotor with a cloth can induce some resonance much like a tuning fork. Something I never really experiences with my Focus Jam2 that had Shimano MT520 brakes and rt66 rotors. After many tries at freeing up pistons and bleeding I finally decided to try a set of Shimano RT66 203mm rotors using a 1.5mm shim on the back and the Shimano 203mm mount on the front of my Lyrik Ulitimate fork. Noise gone!!! But I've noticed another issue and that is I happen to have Shimano rotors from two different countries that are wearing differently. The front is Japan, purchased with factory packaging from Jenson and the back is from China, purchased from Commencal and inexpensive when I could not find any of these available anywhere. The Commencal part came in OEM packaging and not the std Shimano box.
You can see from the photos that the back brake from China has very obvious spots that don't contact the pads and this is distortion from the punching process used in manufacture this part. I have heard that Shimano has moved the manufacturing of this rt66 rotor and other low cost rotors to China. So it's likely that future boxed versions of this will also come from China and may suffer from this manufacturing defect as well. For that reason I'm currently waiting for the rt76 to come back in stock. Everyone seems to be out of many 203mm rotors. For now the brakes function and are quiet. I doubt that the back brake has optimal stopping power but I intend to just use it for now until I wear it out. I've emailed Commencal about this. Their rotor only cost $28. compared $47. at Jenson (but none in stock) so it's a case of getting what you pay for I guess.
