I've drawn a total blank with my rear brake. Basically I can't get close to the wheel locking out. Even with brake pedal fully compressed it still rotates. I think I've done everything to remedy the situation and this includes :-

- New pads which are 1 trial old.

- System re-bled. No air in system and good feel on the pedal.

- Pads cleaned after last trial and didn't seem contaminated.

- Pistons moving nicely in caliper.

- Disc rubbed down and cleaned with alchohol solution.

I really have drawn a blank. I had a dreadfull scorecard at the last trial as I just couldn't stop going down any of the big drops. Any ideas fellas ?

Gaz

Edited March 11, 201115 yr by gazzaecowarrior

No air in system

Fancy a wee small wager on that ?

Yes i do

OK, a soapy tenner says, you still have air in the system.

OK, a soapy tenner says, you still have air in the system.

You under estimate my ocd and attention to detail. The pedal is not spongy in the slightest.

OK, a soapy tenner says, you still have air in the system.

i would say air in system aswell .. pig to bleed 100%

only other possibilities i can think of are contaminated pads . glazed disk . leak on master cylinder seals or disk worn over limit so pads cannot get a grip of the disk.

i would say air in system aswell .. pig to bleed 100%

only other possibilities i can think of are contaminated pads . glazed disk . leak on master cylinder seals or disk worn over limit so pads cannot get a grip of the disk.

I would go with the latter. I will try my spare wheel tommorow and see if the disc on that helps

The pedal is not spongy in the slightest.

Your point is caller ?

Air in the brake line causes the spongy sensation. Air is easier to compress than brake fluid. My brakes don't feel spongy.

Air in the brake line causes the spongy sensation. Air is easier to compress than brake fluid. My brakes don't feel spongy.

OK fella, you know best

Get you a bottle water, run the bike up through the gears an do 2-3 good stops from 30-40mph to warm the disc, then douse it with the water to shock cool it. Do this 2-3 times then allow it to cool and resume normal operation.

If this is not quite enough, start process over.

Your new pads need to "cure" in and this takes a bit of thermal cycling to firm up well.

Edited March 12, 201115 yr by copemech

Gaz you did not mention entirely how it started, I would try new pads if you really think no air in the system. Rear brakes on a Beta is the worst to bleed. I have spent days to get it right.

Get you a bottle water, run the bike up through the gears an do 2-3 good stops from 30-40mph to warm the disc, then douse it with the water to shock cool it. Do this 2-3 times then allow it to cool and resume normal operation.

If this is not quite enough, start process over.

Your new pads need to "cure" in and this takes a bit of thermal cycling to firm up well.

I agree with copemech, i was going to suggest the same. If you get them hot enough first time, it should work a treat.

Should be fairly easy for you if the wheels not locking up. Get riding around with the brake on, and don't come off until you stop to chuck water over the brakes. You know you've done it well you can't see for steam!!!

Thanks fellas for the above responses. Will try the above water trick as I did it before and it helped. Sadly the last trial I did permitted no riding before the event so I couldn't see if my brakes were good after I changed my pads. It was only in the first section I realised I had problems. Various adjustments through out the trial involving turning out the plunger thread imporoved things but were still nowhere near close to locking up. I had a look at the pads yesterday and Im concerned how much wear they had after one trial considering i had no real brakes. I will also take a micrometer to the discs today. Im going up to 'Betabonkers' house today and he's going to have alook at it too. Two heads are usually allways better than one.

Gaz you did not mention entirely how it started, I would try new pads if you really think no air in the system. Rear brakes on a Beta is the worst to bleed. I have spent days to get it right.

It started when I put on new pads. Bike was fine before that. I agree with you about how bad the brakes are too bleed. I started by back bleeding mine.