I have a new bike with SLX brakes and RT-66 220+203mm rotors (produced in China). Front rotor makes sound above certain speed or during some bike lean, rear one took a while to bed in, but still I feel lower power than in my previous bike on different rotors. I'm considering a change RT-66 to something based on aluminium spider/wider more stiffer. What I have found on the market:
- Hope floating – they make 220 and 203 variants, BUT internet says they tend to collide with Shimano caliper adapters…
- Magura MDR-P – cheaper, 220+203 BUT… seems to have rattling issue https://www.youtube.com/watch?v=yy5UxwV5MHo (found a few similar videos)
- Swisstop Catalyst PRO – 220+203, not too many reviews
- Galfer makes 223 instead 220, so they require different adapter, not floating, but wider, BUT also right now they are twice more expensive (Galfer Shark) than e.g. Magura, poor availability
- Shimano Ice-tech RT-M905 – only max 203mm, if I would decide to go from 220 to 203, I would need new adapter
- Sram HS2 etc – there is 220, but no 203 variant. I've checked and there is no way for me to fit 200 rotor properly.
All those facts make me consider Catalyst PRO 220mm+203mm or RT-M905 2x 203mm. What would you choose?
by mszarawy2
3 Comments
I really like my galfers, but they were some money. Those with my V4s are amazing.
Those rotors give plenty of power. What brakes, pads and rotors were you running on your previous bike? What pads are fitted to your SLX brakes?
Swapping rotors for another brand will rarely give you a magical power increase unless your issue is fading due to heat.
As for the rotors contacting while leaning the bike over – again – changing brands will not fix this. This is not a result of anything to rotor is doing, what you are experiencing there is going to be down to some flex in your fork/hub moving the rotor in relation to the caliper.
Get better rotors if you want to get better rotors, but don’t expect it to fix the issues you described.
I run those Magura’s with my Saints, I did get that rattling issue but after 2 years and maybe 600k of vert. I didn’t even notice it while riding, just when sitting on the bike and holding the brake lever, it felt more like a hub with really low engagement. I love the rotors specifically because they are thicker than the stock Shimano ones and I feel like that helps keep the bite point consistent.