| Hold on thar just a minute....!
Before you splash out £300 on new discs, take a few minutes to check out the 'buttons' that mount the ones you have now.
The discs should be semi-floating and are allowed to do this by the round buttons that sit between the rotor and the hub mounting carrier.
Can you move these buttons easily, turn them round in situ with just a finger on either side?
If not this could be your problem - the disc is not being allowed to move and is therefore being held at an angle that gives the impression that it's warped.
Take some WD40 or similar and a toothbrush and get to work at lubing and cleaning up the buttons, particularly the groove in which the rotor sits. Once this has been done and the buttons all move round freely, use plenty of brake cleaner to remove the lubricant from your brakes (if you don't they may not judder but they won't stop you either!) and see if that makes the difference.
I did this on an Aprilia Mille (same Brembo set up as my '99 SPS) and the transformation was amazing. It had previously judddddddderrrrrrrrrred all over the place under braking but suddenly ran almost perfectly smooth even with under the hardest lever pressure.
It tunred out that the discs were slightly warped, but this was only noticable below 10 mph as a gentle grabbing and letting go as you slowed to a stop.
Sold the bike nine months and a track day later with the same discs on and not a hint of judder.
Giles  |