Juicy 3 Question
I just got a 07 Specialized P All Mountain brand new from my LBS, he had one that never sold and gave me a deal. Anyways my front brakes rubbed and didn't have good bite. Took it in and he bled the system and replaced the front pads. After a few days and they started rubbing again but now I notice a significant difference in they don't grab as well. The pads he replaced them with are red instead of the stock black. Do I need a new rotor, and whats with the red pads? Could it also be the pads are not bed/broken in yet? Thanks in advance. Jeff
Welcome to MTBR!
Originally Posted by jeffbum
I have a few questions, how long was it between the time you bought it, and the brake bleed?
On to the pads. The pads that come stock from Avid are steel backed pads. The ones that have a black backing are the bulk ones that can be purchased by a shop to keep the cost of pads to the customer down. They are a little lighter than the stock ones, they are organic pads with Steel/Alu backing. They offer less wear-in time and better power, so I can see why your LBS put them on.
The Rubbing could be from a number of sources. The pads could be making contact w/ the rotor at different times, so the pads are wearing differently, or your brake caliper could be out of alignment with the rotor. To align it, take a 5mm Allen/Hex wrench and loosen the Avid Caliper Positioning System (CPS) bolts, which are the ones that hold the caliper to the adapter, not the adapter to the fork. After you have loosened them, grab the lever and hold it; because Avid has the CPS bolts which are a series of concave/convex washers that align the rotor both horizontally and diagonally so the rotor is perfectly centered. While you are holding the brake lever, tighten the CPS bolts again and release the brake lever. Then spin the wheel to see if your brake centering worked. If it didn't, I normally repeat the process. If repeating it does not work I use the "card trick." This trick is when you can see the gap between the rotor and the pad on either side of the rotor and none on the other side (rubbing). After you have identified which side is dragging, loosen up the CPS bolts and put a card (such as a business card, or similar thickness) in-between the rotor and the dragging pad. After you put the card in grab the lever, hold it, and tighten the CPS bolts again.
If the card trick dosnt work, then I will manually align the caliper with a flashlight on the opposite side of the caliper and my eye.
Hope it helps
If you need photos, PM me, I can take some.
Hey thanks for the reply.
It was about 3 weeks from the time I bought the bike to when the shop bled and replaced the pads. I haven't bothered them with the problem yet because I was trying to let them bed in good before I raised a question.
After some street riding today its still rubbing and now my back is doing the same. My rim doesn't really look out of true, I don't even know if that would effect the brakes. It is definitely rubbing at a certain point on the rotor, but to my eye it doesn't look bent. I have also tried to align the caliper myself using the card trick and by eye but I cannot get the inner pad to keep off the rotor. Maybe I will just have to let the shop play with it some more.