Things were going well and I was clocking some decent lap times when I nearly crashed... Got to the end of the straight doing about 240kph and then on the front brake hard going down the hill when my front brake lever suddenly sank all the way to the grip and I lost my front brakes!
Got on the rear brake and managed to scrub off some speed but there was no way I was going to make the corner so I went off the track but managed to keep her shiny side up and stop before I hit the wall- whew!
Pumped the brake lever and the pressure came back, but was still pretty spongy... Got back to the pits and tried to figure out what made my brakes fail. I installed a new ZX10R reservoir a few months ago and bled the brakes myself so I knew there shouldn't be any air bubbles. Fluid level was fine and still quite clear. No leaks. What else can cause brakes to fail like that I wondered?
I looked and it seemed the pads were still ok. Turns out, they weren't! Got home and took apart the calipers and finally figured out the problem.
Here are the pads out of my right caliper-
The pad on the left, which is the outside pad, is cracked. Probably no big deal, and it still has over a millimeter of pad left. That's the pad I can see when the calipers are on the bike. I always assumed that brake pads wear more or less evenly. Looking at the inside pad (the one on the right in the picture above) I now know that my assumption about even pad wear is wrong. The inside pad is down to almost nothing- there is only about a fingernail's width of pad material left!
Left caliper pads were even worse:
Here again, the outside pad is ok, but the inside pad is toast- only a bit of brake pad left, leaving the backing to press directly upon the disc, no doubt creating a lot of heat, but not much braking power.
I actually did a few more sessions yesterday with the bike and only figured out the problem when I got home and took the calipers apart. But I was a lot lighter on the brakes and they stayed with me for the rest of the day.
Lesson learned! Just because one pad appears ok does not mean the other pad is ok! Check ALL pads regularly!
I'm not even sure what kind of pads these were, but I'm replacing them with EBC HH sintered pads and expect good things from them.
Ride On!
Tony