I have a 85 k100rt the right side front rotor is rubbing hard on the brake caliper. The spacers for the wheel are in correctly and the pads themselves are not worn so I am looking for any ideas as too what can cause this. I was up in sturgis and had to have my front tire replaced and I noticed the rubbing on my way back to Denver. Thanks!!

Hi Kallack,
You say it is rubbing the calliper do you mean rubbing the calliper itself or is it rubbing the brake pad on that side and if so is it both pads on both sides of that rotor or just on one side?

Off the top of my head there are a couple of reasons slave pistons can stick out the first being the pressure relief when the master cylinder returns to the released position is blocked hence keeping the pressure on but I suspect that is not the cause here as both disks are not similarly dragging. Have you changed the brake fluid regularly every year? I suspect corrosion may be keeping the piston out and not allowing the natural spring of the rubber bits to slightly retract the piston.
Regards,
K-BIKE

Hi K-Bike,

The pads are releasing its actually rubbing on the caliper itself. I just got the bike a couple of months ago from a guy who had parked it for the last 2 or 3 years and done nothing with it (I believe after wrecking it) so I have gone thru and changed all the fluids and rubber hoses the rear brake res. new battery relubed the bearings in the neck and a thousand other little things to make it so i can ride it again.

Any chance of a picture? I am having problems visualising this.

Hi Kallack, sounds like an ominous coincidence that you noticed it after the tyre was replaced so it does sound like something has not been refitted correctly almost like the caliper is on the wrong side of the fork but I don't think that is possible.

Just wondering if your wheel is symmetrical although only throwing out some wild guesses at this stage.

Kallack, When I first fitted a new front tyre, about 8,000Km ago, I had a similar problem when I went to re-install the front wheel. I couldn't get the discs to line up with the centre of the caliper slot. I finished up clamping the RHS of the axle, then pulling the whole assembly (spacers) tight with the LHS axle retaining screw, and then clamping the LHS forkleg onto the axle. The axle was approx. 3mm short of the end of the opening in the LHS forkleg. Weird, but I couldn't see where I went wrong, and had no dramas at all during the last 8,000Km. I recently replaced the front tyre, and with a scriber marked the position of the end of the axle where it goes through the LHS forkleg. This time though, I had to pull up the axle retaning screw all the way home, as it should be, then bolting up the four axle clamping screws. Weird!

Rick G.