revtothelimit - motorbike forum

Was out on a 20 mile jaunt to the Daughters. I could hear a speed related light clicking/knocking noise. I realized it was brake related after a couple of dabbs of the front brake. Rode on for a few more miles thinking nothing of it. I knew as I came to a set of lights that all was not well. I managed to get off the road ,but the wheel by this time was as good as locked.
The strange thing is , that neither Disc was hot. I would have expected the offending disc/caliper to be.
For a moment I was thinking it was going to be a call for assistance , but then thought I'd try and fix it myself. After all , I was only 6 miles from home. What could go wrong ?
Managed to get the pads out with the aid of the ignition key , turned the bike around and rode home.
I can report that engine braking is good. Rear brake is adequate. But the temptation to use the front is just not natural. I kept an extremely tight grip of the throttle to be sure.
Know I have to find out what's wrong. Everything looks ok, and like I said, nothing was hot.

Over full with fluid and heat made it expand ? Common on track stuff

Not over filled. But I wonder if the small fluid return whole in the master cylinder is blocked.
But then again the piston , or at least one of them must have been returning as the rattling noise would return when the brakes were off.

I've had the piton seal go in a brembo clutch MC with a similar result, but no rattling noise.

Put everything back together this morning. All seemed fine up on the stand.
Went for a 30 mile trip to a mates with 20 of those on a motorway. Didn't touch the front once. Felt the discs and there was no heat in them.
On the return journey took it easy on the motorway , but really abused the brakes for the last 5 miles. All seemed fine so it's a bit of a mystery.

Could be a stone trapped between pad and disk. I it had been heat/friction related you would have smelt it. I had a caliper sieze on my Astra (car) many years ago and you could smell it as well as the car slowing down.

I wonder if it was a stone. Maybe it dropped down behind the pad when I stopped at the lights ,and was dislodged when I took the pads out. ????