Brake Squeal

[Deacon Patrick]

Confirming my understanding, which heaven knows I’ve gotten wrong once before. Grin.

— Brake squeal is most likely due to insufficient toe-in?

— Toe-in should have the front of the brake pads hitting the rim first.

I just changed the Hunqapiller’s pads with the same Kool-stop salmon pads, and now have squeal in the front pad. I’d lessened the toe-in on it because it looked excessive. 

With abandon,

Patrick

www.MindYourHeadCoop.org

www.OurHolyConception.org

[Tim Gavin]

Your understanding is correct, so far.  Toe-in is so-called because it calls to mind a pigeon-toed, inward-pointed stance.  As a shoeless deacon, that image should be easy to picture.  :)

Many people put a shim (like a dime, there are better solutions on the web) behind the rear of the pad when mounting, for a predictable toe-in angle.

Any part of the brake that is loose could be causing the vibration/squeal. 

-- Ensure the brake bolts are tight

-- Check for vibration in the cable or straddle wire.  The tektro brake hanger Riv sells works well to reduce shudder from this area.

Tim

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[Anton Tutter]

My experience with Kool Stop salmon pads (which I use on most of my bikes) is that even when the toe-in is set correctly, they squeal when they are new.  Usually for the first 10-20 miles. Then they tend to settle in and quiet down.  If the toe is set wrong, they will squeal relentlessly. Either they will quiet down shortly on their own, or you just need to tweak the toe-in a bit.

Anton

[Deacon Patrick]

Thanks, Tim! Since nothing else was adjusted, I'll presume my moron mechanic eliminated too much toe-in! Grin.

With abandon,

Patrick

[Mark Reimer]

My 'tool' for toe-in has always been a biz card/credit card. Just thick enough to angle it in. 

[Patrick Moore]

FWIW, the Salmons on my Rivs squeal under hard braking when temps dip much below 50*F. At 60*F, no squeal. Single pivot calipers, but top end ones. And this phenomenon started only a year or 2 ago -- never saw it before. Sanding pads and cleaning rims don't stop it, tho' it mitigates it.

These same pads did squeal when new to these same rims (new pads, old rims; Sun M14A and ME14A respectively) but it took only a month or so for them to mate. Fronts -- both bikes have only front brakes.

[Deacon Patrick]

Huh. I did clean my rims, for the first time ever. Perhaps that was a mistake. Grin.

With abandon,

Patrick

[Lungimsam]

I don't toe in.

I loosen the shoes and I just press the pads flat against the rims at the same time. I use a small bungee cord to hold the brake lever down to hold pads against rim simultaneously while I adjust the shoes up and down tilt/height against the braking surface of the rim 'til I get it them where I want them and then tighten down.

If they squeal, which they normally don't do, I throw some water on them and ride. They bed in fast usually with just a quick ride, and for some reason getting them wet makes the squeal go away.

[Deacon Patrick]

Heaven knows these have gotten plenty wet, between creek crossings, snow, and meltoff. Grin.

With abandon,

Patrick

[Surlyprof]

Keven had suggested that I use a folded over piece of sandpaper to set toe-in.  Depending on the sanding grit (probably greater than 320), I would guess that would put it at about a dime or credit card.  I use Grant's trick of hooking a section of innertube around the brake lever to hold it in place while I tighten it down (http://rivbike.tumblr.com/post/108583281029/eleven-geeky-tips-that-will-ever-so-slightly  Tip #11).  Has worked so far.

John

[Jon in the foothills of Central Colorado]

If the toe-in is set correctly you can try lightly abraiding the pads with some sandpaper. If your rim has a build up of rubber or dirt abraid them with a scotch bright pad or fine sand paper.Clean all surfaces with alcohol.

Hope you get rid of the annoying squeal.:) I know "clean" is not a word you like to use when referring to bikes( Grin)

On Monday, May 4, 2015 at 1:04:02 PM UTC-6, Deacon Patrick wrote:

[hsmitham]

Deacon,

I had this same problem with my slimline koolstop Salmon pads mounted on my Atlantis. I decided to replace them with new http://www.koolstop.com/english/supra2.html

I went with a shorter pad because I felt it would be easier to toe, for me that proved to be the case.

I agree with John about using Grant's trick of securing the brakes to the rim during adjustment, I however disagree with sanding rims and pads. Beyond the toe issue the main culprit is dirty rim surface and brake pad surface. I'm assuming here that you decided to replace the pads because of brake squeal in the first place. And since you ride through some pretty rough terrain, snow, mud/dirt and water there has to be a bunch of dirt on your rims. But now even after replacing the pads and cleaning the rim the squeal remains. Like me you assumed it was a toe in issue/mechanic error. A friend advised me to use lacquer thinner and a green scrub pad to clean both rim surface and now that you've used the pads the pads also. The lacquer thinner will not leave a residue and will properly remove the dirt and grease embedded in both surfaces. Don't confuse other types of thinners as my friend advised they are petroleum based and will leave a residue.

Lastly, on toe. Really the other poster has it right, just lay the pads flat against the rim snug the nut then do your toe it doesn't need a lot just eye ball it as long as the front meets the rim surface first it'll be fine. Take your time it's like meditation.

Let us know how it works out.

~Hugh
Los Angeles, CA

[Deacon Patrick]

Thanks, Hugh. No squealing before changing the pads or cleaning the rims. Now, I just need to be doing well enough to wrench!

With abandon,

Patrick

[Lungimsam]

Do you have canti-s/center/sidepulls?

[Mark Reimer]

It's on the Atlantis, so canti's

On Tue, May 5, 2015 at 4:48 PM, Lungimsam <john1...@gmail.com> wrote:

Do you have canti-s/center/sidepulls?

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[Lungimsam]

I use the Yokozuna/Mathauser salmons riv sells for the R559 brakes, if you have those brakes. No squeal so far. 

[Mark Reimer]

Whoa whoops, wrong thread! Never mind