Dominover

I've got a squeaky front brake issue, and it's not going away. Can anyone suggest how to fix this.
What I've done so far.
- Cleaned the rim with methylated spirits.
- lightly sanded the brake pad surface to remove any metal shavings
-replaced the front brake pads with bran new ones.
-Toe-in . I adjusted the brakes so that the trailing edge touches first.
- I used copper grease between the washers and the washers and the frame where the brakes attach to the frame. (the washers on the back of the brake shoe)
- Checked all the pads for metal shards. They're clean.

I thought the problem may have been due to that groove in the wheel rim. It's part of the wheel. Is that there to efficiently remove any build-up?
Every time I implement one of the steps above, the noise disappears for about 40 minutes of riding, but then the squeaking returns.
This is a very frustrating problem, and I'm not sure how to solve it.

Some ideas:
- Could I somehow isolate the brake pad assembly from the frame with some kind of synthetic washer?
- maybe there's a special cleaning or coating agent for my rims I could use?
- Is there another method of a toe-in I could employ?
- Is there a particular type of brake pad that eliminates noise completely?

Frustrating problem.. Any suggestions would be helpful.
Thanks again.

jaxgtr

What brand of pads are you using? When I had v-brakes, I generally used kool stop salmon pads, and never had any issues with squealing, also Shimano pads were good. I did find that some brands\models of pads have a slightly harder compound and those were a little more susceptible to squealing.

rsbob 

the leading edge needs to be toed in slightly so the tip (toward the front of the bike) touches first then the body makes contact.

Kapusta

Yeah, I might try Kool Stop Salmon.

Sometimes you just get a brake/fork combo that somehow resonate just right and are squeal-prone. Pads might change that.

One time I had a set of XTs on a C-Dale Fatty Headshock that I just could not shut up. On a lark I tried installing a brake booster, and that shut it up completely. I guess the booster did not want to resonate at that frequency. Just my guess.

Dominover

I did that. Even tried it both ways with no affect after about an hour of riding.

Dominover

That's pretty much where I am at.
It's just a bad combination.
I'm wondering where the resonating sound comes from?
Should I put a leather buffer washers between the brake pad assembly and the frame? It's something I could easily make.

If I knew what was actually resonating I could probably buffer it somehow.
Does anyone know where the sound comes from? Is it the rim that's resonating or the vibration going back through the brake pad and onto the caliper and the bike frame?

Dominover

I'll look at those thanks.

50PlusCycling

Play with the toe adjustments, you may have too little or too much. There are lots of recommendations for the Kool Stop salmon brake pads, but in my experience, these were the most squeal-prone pads I had ever tried. I got them quiet, but it took a lot of adjustment and some break-in time.

jaxgtr

I used to use a folded business card or rubber band to adjust the toe. Place it on the back of the pad and then it would set the toe just right. That is the one thing I hated about v-brakes. they were just a little fidgety sometimes.

Kapusta

I never needed to toe in my v-brakes, and it never helped when I had squealing.