I have Shimano XT M765 calipers and used Sintered pads last year in the Alps. They did fine and didn't need changing there with the fronts getting changed last October (Alps was in June) and the rears are still in there....
Was just about to buy another few spare sets but noticed that the text says no to downhill stuff for sintered....
PADS ARE SUITABLE FOR FOR ALL TYPES OF RIDING EXCEPT DOWNHILL. THE BENIFITS OF SINTERED PADS ARE:
* LONG LIFE - AROUND 3 TIMES THE LIFE OF A STNDARD PAD
* SUPERB PERFORMANCE WET OR DRY
* EVEN MODULATION
* LONG LIFE IN MUDDY CONDITIONS WHICH WRECK STANDARD PADS
* PROGRESSIVE LEVER FEEL.
Can anyone explain why they're not suitable for DH?
???

