Want to change over my brakes from Sram to Shimano but don’t want the expense of new rotors. Will a shimano calliper with a 203mm adaptor work with an avid 200 rotor? As the rotor is smaller than the caliper I would assume to lose 1.5mm on the caliper could entail filling it down if there isn’t a washer you could just take out.

Why not use existing mounts?

I don’t think sram mounts work with Shimano calipers. Swapped a mates avids to Shimano slx yesterday and the bolts were the wrong length as there were cone washers on the avids. Suppose could just try Shimano bolts on sram adaptors.

Maybe, I had a right palava trying to get shimano 180mm rotors to work with shimano brakes and avid adapters.

Try it, worst that happens is you need to buy the right rotors and adapters anyway.

And that’s in spite of the fact that avid do 180mm rotors and 185 versions, and I was only swapping from 180 to 180!

SRAM mounts should work fine with Shimano callipers. Just swap the calliper only leaving all the other bolts/washers/conical washers etc. exactly as is on the SRAM brake. Sometimes, as SRAM callipers are slightly thicker at the bolt hole than shimano you might need to add a washer (1mm say) under the bolt head to effectively make the bolt 1mm shorter or the bolt may bottom out in the post hole if a post brake.

EDIT – but a 200 SRAM mount is almost identical to a 203 Shimano mount just 1.5 shorter…. Just bolt the brake to that!

I had trouble getting a good lever feel when I put Shimano brakes on avid rotors. Changed to superstar rotors that were visibley thicker get a good feel

I had trouble getting a good lever feel when I put Shimano brakes on avid rotors. Changed to superstar rotors that were visibley thicker get a good feel

Your pads will also be overhanging the edge of the rotor, won’t they? So there will be a) slightly less contact area between pad and rotor,and b) a danger that if they wear enough, the unworn part of the pads will actually touch, severely reducing braking performance, potentially very suddenly?

I had trouble getting a good lever feel when I put Shimano brakes on avid rotors. Changed to superstar rotors that were visibley thicker get a good feel

I wondered if the slightly worn avid rotors where effecting the lever feel when I put shimano XT brakes on. But the avids are coming up ~0.25mm thicker than the new shimano rotors on the other bike. I wonder if the superstar rotors are even thicker. Maybe I just need to get round to bleeding the brakes.