I think l know the answer, but I'm getting a pretty good shutter with hard front brake application. Pads were replaced about 1500 miles ago. The rs has the dual front disc with the holes. I'm thinking the most likely culprit is one of the discs is a little warped. I know they can't be "turned" but is grinding or machining of some sort possible? Other than a warped disc, any thoughts about a less costly culprit? Bike was put back on the road last year after a 25year nap. 19,000 miles on it.