[MattW]

I'm getting a really loud humm from my rear Hayes disc brake. It's an 8" rotter on a VPS fluid.

I have a D321 built up on a Formula rear DH hub( regular Q/R). It has cartrege bearings. The drive side is laced with a regular 3 cross pattern. The disc side is laced with a 3 cross pattern, but all the spokes are laced to the outside(ie. all the heads that fit into the hub are facing inside, not alternating one in one out).

I've tried cleaning the disc with alcohol. So my question is, is this comming from the disc, bearings, spokes on the drive side? I've replaced the bearings but the wheel always sqeeled.

I think it might be the drive side spokes. If it is, how should I have the spokes relaced?

thanks
Matt

 

[El Jefe]

Originally posted by MattW
I'm getting a really loud humm from my rear Hayes disc brake. It's an 8" rotter on a VPS fluid.

I have a D321 built up on a Formula rear DH hub( regular Q/R). It has cartrege bearings. The drive side is laced with a regular 3 cross pattern. The disc side is laced with a 3 cross pattern, but all the spokes are laced to the outside(ie. all the heads that fit into the hub are facing inside, not alternating one in one out).

I've tried cleaning the disc with alcohol. So my question is, is this comming from the disc, bearings, spokes on the drive side? I've replaced the bearings but the wheel always sqeeled.

I think it might be the drive side spokes. If it is, how should I have the spokes relaced?

thanks
Matt

I'm willing to bet it's the caliper alignment. When one pad hits before the other, it causes the rotor to hum.
Loosen the bolts holding the caliper to the adapter, stick a couple business cards between the pads and the rotor (one on each side) and then tighten the bolts back down. The pads should hit evenly and your hum will be gone.

 

[El Jefe]

Oh yeah, pull the cards out before you go ride again.

 

[MattW]

thanks for the reply. I went down to UAP auto parts and picked up some anti squeel compound for car brakes. I smeared it on on every surface where my disc contacted the hub and bolts. It seems to be working. We'll see tommorrow when I ride.

matt

 

[El Jefe]

I'm glad you have silence, but don't forget to check the caliper alignment too. Not only will aligning the caliper permanently solve the hum problem better than a quick fix spray, but your brake power and modulation will improve. Good luck!