| One of your discs may well be warped. If you can put the bike on a front paddock stand you should be able to tell by holding something like a small wooden stick (a chopstick would be fine - don't use a screwdriver and gouge your disc) up against the fork stanchion at right angles to the disc. If you butt the stick up to the disc in question, and then leave a very small gap, it should be quite clear if the disc is warped 'cos the gap will either increase and decrease as you turn the wheel, or all the clearance will be used up. That'll mean that the disc is warped or it's not sitting on the carrier right.
One thing to check though is that all your semi-floating buttons are actually semi-floating. I had a big amount of pulsing on my bike and it turn out to be crud behind one of the buttons that had stopped the disc doing any type of self centreing. Out with the WD40 and an old tooth brush and scrub them up - worth a try and could save you big bucks. Take your calipers off first though so you don't get any WD near your pads, try not to get any WD on the discs swept surface and make sure that you degrease the discs thoroughly as a precaution. Worked for me.  |