| Wavey discs...
The original concept of these was so that the edges of the the disc would run across the surface of the pads and shave a tiny layer off, this was supposed to stop the pads glazing. Negative effect of course was the pads didn't last very long!
I may be wrong, but I think the first team to use them was Padgetts? Kev is gonna tell me I'm wrong!
But we have them on road bikes just cos they look flash! | 
Threaded Mode