do rotors matter?
i just upgraged to hydraulic brakes (xt m765). got em off ebay. i paid extra to have the seller throw in some rotors; he didnt know what kind they were. i got em and theyre rt61 whereas the shimano website recommends rt75s rotors with these brakes. does it make a difference? i mean, enough to return mine and upgrade? and if it does, does anybody know the difference between rt75s and rt75dh rotors? im assuming the dh is for downhill, but does that matter when it comes to rotors? thanks for any help.
The RT61 is the Deore level rotor, and it has a wider, less drilled braking track than the XT rotor - the RT75. The RT61 will work. The only time there is a drama is if the rotor's braking track is narrower than the brake's pads, as you will get uneven wear on your pads. I can't be sure, but I think the RT75DH will be a larger diameter (8 inch) rotor, compared to the standard 6 inch XC rotor. You'd need adaptors to move the caliper further out to run the bigger rotor.
Sideknob is right, the DH is the 203mm XT rotor, while the S is the 160mm.... There is no problem in running the deore rotors.... you can even use rotor from other brands, as long as the brake track is wide enough (Shimanos are usually the thinner ones)