The rubber compound on one side of each brake caliper (front & rear) is wearing down about 2X fsster than the rubber compound on the other side.
The installation directions from the shimano website suggest that the calipers aren't properly centered on the wheel. Is that is what is causing this problem? Has anyone had this experience and found a solution?
Dual pivots, no? When you press the lever, does it look like both are contacting the surface? If not, you may have to adjust them to balance
Scroll down to #5:
"1) One pad might be ""toed in"" more than the other so it's hitting on a smaller surface area and wearing faster. If so, than the front/rear of the pad should be of different thickness.
2) You have a slightly raised seam on one side of the rim. Very gently sand down the rise with a fine emory cloth.
3) Somewhere along the line you got a set of pads that were from different batches -- one older/harder than the other.
4) Per answers above, you've got the caliper misaligned *and* you're setting the clearance so tight that one side is constantly dragging the rim.
"
Frame is new, brakeset is new, brake pads are newly manufactured. I checked the dish of the wheels and they are fine. Calipers are centered on rim, none of the brakepads touch the rim, and I don't use a toe-in adjustment on my brake pads. So far, I have 4,500 miles on this bike in a year and am on my third set of brakepads.
After my ride this morning, I noticed on both my front AND rear calipers that the brake pad on the opposite side of where the brake wire connects to the brakeset is the one that is wearing more quickly. I can only assume that it is the design the Ultegra 6600 brakeset that causes the brakepad on one side of the caliper to wear more quickly than the brakepad on the opposite side.
If everything else has been ruled out (return spring placement and tension?), you could purchase one set of Kool-Stop black pads -- and one set salmon-colored -- and install one of each color on each caliper.
Since salmons are softer than the blacks, they'd go on the cable side -- and the longer wearing blacks on the non-cable side.
Bass-ackwards and wierd looking but I don't think it would negatively affect braking performance.
If you have checked everything else that you mentioned, I agree with Neile re: spring tension. I had the same issue on an older bike even though I checked the centering on the brakes constantly. Bike shop mechanic told me that sometimes there is an imbalance with the spring tension. Short of changing the spring, bike mechanic told me that there is not much that you can do.
There is something you can do: bend the springs. And get a new mechanic.
There is an adjustment for spring tension according to the Shimano Ultegra 6600 service instructions. I'll make that adjustment and see over the next two weeks - 500 miles.
Spray a little lube into the pivot points. It wouldn't be the first time Shimano was stingy with lube.
Do I need to point out the obvious, what happens if you get it on the brake pads? Nahhh, didn't think so.
"""Do I need to point out the obvious, what happens if you get it on the brake pads? Nahhh, didn't think so.""
Well, your brake pads would last longer (even if you don't)."
Thanks Evan. I re-read the Park Tool repair tip on checking for binding on each of the brakesets two pivot points. I'll take the brakesets off the bike, remove the spring, check for any binding, and lube before re-installing.
Seems strange to do this on a new bike that hasn't been ridden in the rain. But, who knows.
Tonight, I worked on the brakesets and found that the cables were flattened at the point that they went through the screw barrel adjusters on the brakesets. This caused them to hang up one side of the brake arm/pad on each brakeset.
I replaced the cables, brakepads, and cleaned, lubed, and adjusted the brakesets. Time will tell, but I believe this was the root cause.
Thanks for all the input.
>>the cables were flattened at the point that they went through the screw barrel adjusters<<
Both cables? Clearly a case for Sculley and Mulder.
