I have a weird and annoying problem on my front Oro Puro.
It seems that the master cylinder is not able to compensate for pad wear- to explain with an example:
I put new pads in, and after bedding'em and centering the calipers, I race a 50Km marathon event. The brake feels perfect at the start, but by mid race the lever throw is increasing (not related to overheating), and by the end of the race, the lever almost touches the grip – even when the brakes are completey cold.
At home, I pump the levers a few times, and the situation doesn’t change. So I remove the wheel, pump the lever a few times, and see that (obviously) the pads come closer to each other.
Now I space the calipers apart with a screwdriver, mount the wheel an recenter the caliper. After pumping the lever a few times, now the pads contact the rotor with a very positive feel and the lever throw is perfect: not too tight, not too "slack". So far so good, but during the next long ride the lever throw problem is occurring again. By the end of the ride, the lever is almost touching the grip.
At first I was thinking that the reason of this weird behaviour was a system underfill, so repeatedly bled the brake, with no result. The lever feel is very solid, so probably no bubbles in the fluid. I also tried to bleed the damn brake using an old set of worn-out pads, just to have some extra fluid in the system. No results.
The rear brake has a very consistent feel, and the lever throw remains the same throghout the entire pad life – as it shouldbe on any good disk brake system! The same pads -formula organic- are used front and rear.
Hope the problem description is clear.
Formula experts, any advice to trobleshoot this? Thanks in advance
PS
for simplicity, lets assume the FCS lever position wasn’t moved in the process, so let’s keep the FCS out of the picture
It seems that the master cylinder is not able to compensate for pad wear- to explain with an example:
I put new pads in, and after bedding'em and centering the calipers, I race a 50Km marathon event. The brake feels perfect at the start, but by mid race the lever throw is increasing (not related to overheating), and by the end of the race, the lever almost touches the grip – even when the brakes are completey cold.
At home, I pump the levers a few times, and the situation doesn’t change. So I remove the wheel, pump the lever a few times, and see that (obviously) the pads come closer to each other.
Now I space the calipers apart with a screwdriver, mount the wheel an recenter the caliper. After pumping the lever a few times, now the pads contact the rotor with a very positive feel and the lever throw is perfect: not too tight, not too "slack". So far so good, but during the next long ride the lever throw problem is occurring again. By the end of the ride, the lever is almost touching the grip.
At first I was thinking that the reason of this weird behaviour was a system underfill, so repeatedly bled the brake, with no result. The lever feel is very solid, so probably no bubbles in the fluid. I also tried to bleed the damn brake using an old set of worn-out pads, just to have some extra fluid in the system. No results.
The rear brake has a very consistent feel, and the lever throw remains the same throghout the entire pad life – as it shouldbe on any good disk brake system! The same pads -formula organic- are used front and rear.
Hope the problem description is clear.
Formula experts, any advice to trobleshoot this? Thanks in advance
PS
for simplicity, lets assume the FCS lever position wasn’t moved in the process, so let’s keep the FCS out of the picture