So...I was told by a mechanic that my front brake disc is warped.. I don't see anything wrong with, neither does another mechanic that I went to. So a couple of days ago I left my bike out (sheltered area) except for the front tire bit in the rain and wind. I came back to it 1 day later, my front brake disc has rust on it? I wiped the rust off, and went for a test run, still works fine, after applying the front brakes during my test run, I came back and it was all fine (looking normal as well) oh and when I put the bike to N and let it roll, I can hear little noises like screeches, sounds like the front brake pads are rubbing against the disc, however the front brakes werent applied So what do you guys think? And also to install/replace the front brake disc is it as easy as taking the front tire off and then unscrewing the allen keys off the front brake disc from the rim?