[moltuae]

Originally Posted by The_Laird

I've also read that warping a disc is a pretty unlikely event - just how hot would they have to get to warp that much metal anyway?

I had a long running battle with this too and, whilst I agree that bushes are a likely candidate for the cause of the problem if it's shuddering when you're not braking, other factors may be in play, as David suggests.

My problem started after I'd had new discs, refurbished calipers and new pads. It was great for 2-3K miles, then the shuddering started and got worse. New discs and pads under warranty cured it, but the same happened again after 2-3K miles. And again!

The cure was to get the discs skimmed in situ. They weren't warped, just not quite in line for whatever reason. And it was confounded by a rear caliper seizing a little. Been fine now for at least 15K miles.

That's generally my experience too; great at first, then 2-3K miles later ...

I guess once they've bedded in, and friction improves, any minute difference in rotational disc-to-pad distance becomes noticeable.

In fact, I had new Brembo discs and pads fitted all round just a few thousand miles ago, and they've just started juddering a little. And since I had just about every arm, link and bush replaced on the front suspension around the same time, I can pretty much rule out any other cause.

I think skimming discs in situ is the only way to ensure the disc spins true and isn't affected by hub/mounting imperfections. I plan to get my discs skimmed in the next few weeks.