losing the back under front braking...sometimes?

[darrsi]

My reason for saying that being that in a car I had a terrible juddering when braking heavily from speed, yet normal braking at normal speeds was unaffected. Turned out the discs were badly worn and replacing them was the cure. Now I assume am MT, a couple of years old won't have worn discs, so I mention warped. Possibly just slightly untrue just enough to give the heavy braking symptoms.

We're talking about semi floating discs though, it would take some savage race type maniac braking to warp them through heat for example.
Sticking piston certainly could cause issues but i would've though Val would've picked up on that earlier.
He actually described perfectly what i was getting before, as if you are braking on a cobbled road.