[DhDork]

Got a customer who bought a 2010 Giant Trance from us a couple months back. About 2 months ago he brought his bike in complaining of a howl coming from his Elixir 5's. So, I cleaned up the rotor and caliper with alcohol, sanded the pads, rode it through the lot, and sent him on his way. Brought it back after a ride with the same complaint. So, this time, I repeated above process, and bled it. Again tested it and seems good. Brings it back again, and insanity ensues. I now decide to go on a ride with him and check this thing out for myself. About a mile into the ride, we start the decend and comes the absolutely horrendous howl, pretty much dead on with contamination. We get new pads and a rotor. Install, and bleed, and send him out. Comes back again, we call Avid, they send us new rotors and pads. Then they sent us a FULL new brake, this time its a F160mm with a R hose instead of a R185mm, with the 185 rotor on backorder. Comes back with the same problem. We get the new rotor in, I sanded the pads, cleaned the caliper up, and I rode it through the lot just now. After a few slow downs, I am now back at the same spot. Also somewhere along the way, thinking it could be something on the bike vibrating really bad, we swapped out a Hayes Stroker on to his bike from another from his stash, and no problem whatsoever.

Any suggestions? I haven't bled it since we got the new brake installed, and I'm going to try that right now. But I'm pretty damn sure that's not going to work.

 

[Mr Jones]

Chances are the bottom of the pads are touching the rotor spokes. I had a similar problem with my Elixir CR's a few months ago. Put the thinnest washer I could find between the CPS hardware and brake adapter. No more noise.

I've heard of a different fix, but have yet to try this specific method. Remember the brake pads for the old caliper brakes? Remember those concave and convex washers that were included in the pack of brake pads? Don't they look surprisingly similar to the AVID CPS hardware, just a little thicker? Heard of someone using one concave and one convex washer in place of the CPS hardware, between the caliper and the brake adapter/post.

 

[DhDork]

I have noticed on several of these pads as I went back to sand them, that the metal backing, face up (left pad in photo) , had been glossy. I thought that was only the shine of the metal. Only this time have I noticed that there is some fluid on the back of the pad (right in photo), and one of the pads isn't glossy. It was glossy on every other pad, both sides. Could it be the pistons are leaking and causing the pads to become contaminated?

I did replace the cup and cone washers with just one solid washer underneath between the caliper and the adapter that was same size as the cup and cone washer. Thought maybe the cup and cone washers were vibrating. No go. I'll have to try the larger cup and cone washers from a v-brake pad. Tons of those lying around.

Now I do remember the old Juicy rotors (1st gen) rubbed on the spokes of the rotor a hair. This caused a low pitch chirping nose, but not a howling consistent with something you would hear from say... riding through a creek. That's what this is.

Also I have noticed that the pads tend to shift in the caliper. I know my pads in my Juicy 3's do this on my trail bike, and I've never had howl. So I've looked right past it.

I've decided to put it aside for now, as he has bought a whole new bike anyways. Way sicker than his current rig.