I had new discs fitted before this year's jaunt + new brake fluid etc.  On the way down I treated them sympathetically but those downhill hairpins led to the discs getting a bit warm and this has caused them to run out of true. I have not measured the run out yet but braking is now accompanied by a judderring through the steering wheel.  
 
My man tells me that he bought them from his local factor.  This probably means that they were machined from the solid in a third world country. In days of yore they would be cast and left to rust in the yard for a few months before being cleaned up and sold. These would alst for many years. Now it appears that discs might have to be regarded as a service item.
 
Grooved and vented discs are available from Minisports at £90 the set.    Does anyone have any idea about the utility of these discs and whether they would be likely to remain true under downhill braking???
 
 
regards
 
Tom
Team 55

Phil,
 
Many thanks for this. I'll check the resources site and thanks for the heads up on thicknesses. I had not thought about this!!
 
My co-driver Geoff Giles took a camera and is putting all the pics on a cd for me.  I'll see about sharing the best of these.  
 
 
Regards
 
Tom
TEAM 55