girona

Ok, I've run into a wall.

I didn't make the connection at first, but my new wheel is causing my Avid BB7 front disc brake to squeal like mad. It's been a long process to figure it out. This is what I have tried to eliminate brake squeal:

-Organic pads
-New rotor (Shimano XT instead of Avid 160mm)
-New comprensionless housing and cables (Avid Flack Jacket)

Then I decided to dig out my old front wheel and mount the original Avid rotor: no squeal. Must be the new wheel then!!!

The bike is a 2008 Salsa El Mariachi with the original rigid steel fork.
Old front wheel is an XT hub/ Salsa Semi.
New wheel is a WTB front hub/ Stans rim.

It squeals in dry and wet conditions. It does so only when braking softly to medium strength. When braking hard, the squealing dissapears.
It is like the squealing is resonating through the wheel and fork and transfering vibration to the handlebars.
There is no noticeable play on the front hub.

Do you guys/gals have any suggestions on how to go about getting rid off the squeal?
Retension the wheel maybe?


I really don't know where to go from here and I would like to use keep using the new wheel...

FBinNY 

Give the new rotor a chance to break in a bit. You might also remove the wheel and clean the rotor with a solvent such as mineral spirits, or naphtha (keep away from brakes and pads) to remove any residue from the manufacturing process.

To speed the break in use this trick from the auto and motorcycle world. Do a series of hard breakings as in emergency stops. This breaks it in much quicker than normal slowing and controlled stopping. Being basically lazy, I'd try the hard breaking trick before bothering with cleaning.

coldfeet

You could also check the rotor is properly screwed on, use a good fitting tool and don't go nuts, proper torque wrench is a good idea.

girona

Thanks for the replies.
The rotor is properly mounted on the hub.
I will keep using it like it is and see if the squeal goes away. I have a feeling it won't, though.

ruindd

Ummmm, Mineral Spirits might be really bad for your pads. I know you're saying just to clean the rotors and not the pads, but I strongly recommended using rubbing alcohol.

I had noisy rotors until I trued them really well. I went all out and got some drumstix and dial from Paul Morningstar

mobaar

Did you bed in the new pads/rotor per Avid's instructions?

On my BB7s, I would get squealing if I cleaned the rotor with alcohol, but it was quiet if I used Windex.

SlimAgainSoon

Windex? Go figure.

I had a BB7 get a bit noisy. I checked and the converter needed to fit the rotor to the wheel had gotten a wee bit loose.

Tightened that up and straightened things out and it went away.

girona

I will try the Windex trick.

BTW, my hub and disc are the standard 6-bolt affair.

As far as bedding the pads go... When I first installed the new wheel, I used the original rotor and pads. From the get go they were howling and haven't been able to quiet them down.

I do have a new suspension fork waiting to be installed. I wonder if it will make a difference compared to the steel rigid fork mounted on the bike at the moment.

mobaar

Yeah.. not sure why Windex worked, but with alcohol it would squeal like crazy even just rubbing a paper towel over the rotor.

The pads/rotors definitely need to be bedded in though. Check the manual for specifics, but its basically getting up to 15-20 mph, then slowing quickly down to 2-3mph. Then repeating 5-10 times.

MilitantPotato

If your rotor has an aluminum carrier, keep windex away from it.