Googling rotor rub will likely leave you with two suggestions. First, try centering the caliper by loosening the caliper, holding down the brake and re-tightening it. Second, full reset. Remove the brake pads, push in the pistons. Center the caliper. If neither of the two work, then some will try checking if their rotors are bent. I’ve gone through this route minus checking for rotor bend (as it is very unlikely) and it usually works. But some times, a little rub remains. Nothing major, wheel spins freely but there is that very very faint brush that is barely audible. Still irks me. I thought I had to live with it. Until I stumbled on this little rotor alignment tool. Here it is.
The tool is extremely simple. It is a thin u-shaped piece of metal that wraps around the rotor. What it does is to add around 1-2mm of additional clearance to the rotor.
Slip it between the brake pads and then re-center the caliper. I had difficulties slipping it between the brake pads, so I did a full reset and pushed the pistons back. Caliper was then centered with this tool in place. Quick spin test. Silence. Perfect.
Highly recommend this tool if you have disc brakes. Some wheels come with an adjustment tool like this. Some don’t. If you don’t, just grab one. I got mine from Shopee for just a couple of dollars. Well worth it.