BigJohnBreva
Just got it firing!
- Joined
- Jul 8, 2012
- Messages
- 1
I thought its worth posting my experience with solving the "warped disc" problem I've had with my Breva 1100 since I purchased it in 2012. Sorry about the length, have a nice cup of tea ready....
My story....
Bike had about 800 miles on it when I bought it from the original supplying dealer who'd bought it back from the original owner who'd hardly used it. Almost from my purchase the brakes were a bit dodgy - lots of jerks and pulsing at lower speeds - although at higher speeds it was OK.
Over the next year (I do c. 2,500-3,000 mls a year) it got progressively worse, so after trying the usual brake bleeding, new pads, all the bobbin cleaning methods recommended on here, plus suspension adjustments etc, I bought a new set of Viper discs (from M&P here in the UK) and new pads. These were fitted and initially were OK, but within 1000 miles the problem was back. Much cleaning of discs and pads ensued plus another set of sintered pads. Any improvement did not last very long.
I managed to get 2 MOTs with this set up but by 2015 I was fed up with it so I went for a set of EBC disc from Gutsibits and a set of HH EBC pads. this seemed to work OK for the next year or so, but by about another 4000 miles the pulsing was back. And it failed an MOT "Front Roller brake test indicates excessive fluctuation of brake effort" The tester passed my retest as I managed to improve the braking a little (and he felt sorry for me, he said). Interestingly, although they are a big dealer in 2nd hand bikes, they said they would never touch another Breva as they had a similar situation on one a few years earlier even they couldn't 100% cure.
So in summer 2017 I went to town on the problem. I changed wheel bearings, added stronger fork springs from Hagon (I could bottom the forks very easily with the old ones, even with full preload ), checked all head bearings, disc run-out checked with dial gauge, disc thickeness micrometered every 30 degrees (all fine). I stripped down the calipers to check pistons (all absolutely perfect inside) and lubricating with brake grease etc. All pistons moved in sequence with each other and were movable with finger pressure. No drag between disc/pad.
But I still had the pulsing. 'kin hell.
Rather than fail another MOT decided to try new caliper seals as a last resort. As you may know, rebuild kits are not available from Brembo, but on UK ebay I saw a set advertised:- https://tinyurl.com/y7mratw4
I fitted the kit and the result was like night and day - no vibration, smooth braking, perfect.
All I can see is that the pads maybe retract a little more than they did. The kit included the seal between the 2 caliper halfs and a new bleed nipple, so to fit the kit involved total dismantling of the caliper. This maybe removed any blockage/fluid airlock that normal bleeding couldn't get rid of. The old seals had a directional chamfer on them too, very pronounced. BUT the new seals were totally square/flat.
Moral of the story - check everything, check again, then look at the seals....
My story....
Bike had about 800 miles on it when I bought it from the original supplying dealer who'd bought it back from the original owner who'd hardly used it. Almost from my purchase the brakes were a bit dodgy - lots of jerks and pulsing at lower speeds - although at higher speeds it was OK.
Over the next year (I do c. 2,500-3,000 mls a year) it got progressively worse, so after trying the usual brake bleeding, new pads, all the bobbin cleaning methods recommended on here, plus suspension adjustments etc, I bought a new set of Viper discs (from M&P here in the UK) and new pads. These were fitted and initially were OK, but within 1000 miles the problem was back. Much cleaning of discs and pads ensued plus another set of sintered pads. Any improvement did not last very long.
I managed to get 2 MOTs with this set up but by 2015 I was fed up with it so I went for a set of EBC disc from Gutsibits and a set of HH EBC pads. this seemed to work OK for the next year or so, but by about another 4000 miles the pulsing was back. And it failed an MOT "Front Roller brake test indicates excessive fluctuation of brake effort" The tester passed my retest as I managed to improve the braking a little (and he felt sorry for me, he said). Interestingly, although they are a big dealer in 2nd hand bikes, they said they would never touch another Breva as they had a similar situation on one a few years earlier even they couldn't 100% cure.
So in summer 2017 I went to town on the problem. I changed wheel bearings, added stronger fork springs from Hagon (I could bottom the forks very easily with the old ones, even with full preload ), checked all head bearings, disc run-out checked with dial gauge, disc thickeness micrometered every 30 degrees (all fine). I stripped down the calipers to check pistons (all absolutely perfect inside) and lubricating with brake grease etc. All pistons moved in sequence with each other and were movable with finger pressure. No drag between disc/pad.
But I still had the pulsing. 'kin hell.
Rather than fail another MOT decided to try new caliper seals as a last resort. As you may know, rebuild kits are not available from Brembo, but on UK ebay I saw a set advertised:- https://tinyurl.com/y7mratw4
I fitted the kit and the result was like night and day - no vibration, smooth braking, perfect.
All I can see is that the pads maybe retract a little more than they did. The kit included the seal between the 2 caliper halfs and a new bleed nipple, so to fit the kit involved total dismantling of the caliper. This maybe removed any blockage/fluid airlock that normal bleeding couldn't get rid of. The old seals had a directional chamfer on them too, very pronounced. BUT the new seals were totally square/flat.
Moral of the story - check everything, check again, then look at the seals....
