Hi, installing a Grimeca NT front disk brake on a 20mm PX125 fork. Back plate is properly installed (I double checked). Then I installed the hub. It spins freely. I opened the pads on the caliper the full amount. When I try and install the caliper the lower pad is scraping against the disk. Installed the caliper and the hub will not spin freely as its rubbing up against the pad.
What is causing this? How do I solve it? On the inside of the backplate, if I put a washer above the retaining clip, would that raise the hub a couple of mm's so the disk sits clear in the caliper?