Disc brake set up - moving rotor outboard?

luv2ride

Trying to set up my TRP Spyres after some pretty woeful braking performance. After removing and cleaning the OE pads and discs and getting no improvement, I've just fitted new rotors (SRAM Centrelines) and some new Nukeproof pads. On refitting the rear calliper I notice that, under braking, the rear rotor deforms / bends slightly. This is after centering the calliper with the fixing bolts loose to start witw, by applying the brake. As the Spyres are dual piston I'm guessing this shouldn't happen but I can't set it up without the rotor bending slightly when the calliper is applied. It's almost as if the rotor needs to sit another 1-2mm away from the hub. Can this be archieved using spacers or washers? Given that it's brakes I thought I'd ask for advice before attempting a "fix".

cheers

nicklouse

You need to adjust the caliper so there is no disc movement. How does the caliper mount? Post mount then you should have enough adjustment.

Pics as it is now?

meanredspider

Does the disc bend when the screws are loose and the brakes applied? Are you gently tightening the screws alternately so you don't twist the caliper?

am7

Are you sure both calipers move the same amount and one of them is not binding? I would remove the wheel and pads and gradually squeeze the brake while watching the calipers. You will have to push them back in before putting the pads in obviously.

luv2ride

Nicklouse: Bike is a Kinesis Pro6 disc so calliper is direct post mount outside of the rear triangle.

Meanredspider: I didn't do up the two mounting bolts alternately (did one at a time) - seems obvious now you say it so will try that!

am7: Will look at how the calliper acts without the pads fitted. To get the pistons fully retracted, I take it it's best to gently use a large flat head screwdriver to coax them back in? I remember that was the drill on MTB hydraulic brakes anyway.

Will post pictures tomorrow if the above advice doesn't sort it...cheers

nicklouse

So you should beable to move the caliper enough to take out any movement.

Or is it a bend in the pads only as if the mount is not at 90 to the axel.

Also double check that the hub is fully seated in the drop outs.