Berlin

That sounds like the problem Mad Tony had on the track last year. He shimmed the front brake master cylinder with washers so his lever wouldn't come back as far when he braked. Unfortunately, this meant that the master cylinder wasn't returning all the way and the more he braked the tighter the pads got. he locked the wheel solid on the second straight.

So things to check. Are the front and rear levers returning all the way to fully out when you release the brakes? or are the pivots tight and causing the cylinder to pump up? Next time this happens, get off the bike and check the master cylinders for the mechanism binding and bake sure they are returning all the way out.

a little piece of toot or grit in the master cylinder might also do this. The cylinder must return all the way out to release the pressure.

and if you can identify whether its front or back or both (unlikely) then you can isolate the problem to one or the other.

I don't think its sticking pistons as that would manifest itself more often. But its worth checking anyway.

I think you have a problem with your master cylinder(s)

and I'd bleed the brakes too just to make sure there's no air in there that can expand when heated and cause this too. Just to make sure.


Oh and next time it happens (quickly and lightly) touch both front discs (don't burn your finger). If one is hotter than the other, its calipers, if both are as hot as each other, its master cylinder.
C