sbslider

So I will admit I did not search here, but I did read on sheldon brown and did not find the information I was looking for. My front brake pads have been very squeaky with moderate brake pressure for a couple weeks. I tried adjusting the amount of toe in, but no real help. I bought new pads, have not tried them out yet, I will when I ride home tonight. I noticed the old pads are worn though the gaps that are built into the pads. What I mean by gaps is new shoes do not have a completely flat surface for braking, but there are cuts or gaps built in that make the one surface more link 3 or 4 surfaces. Those gaps are gone on both pads, so I figured getting new pads could not hurt. What I am wondering is do those gaps help with squeaking? BTW, my new pads are salmon kool stops.

DieselDan

Have you cleaned the rim? Moisture, or oil, on the rim can cause it to squeal. Clean the rim with some alcohol.

zonatandem

+1 on cleaning rims with alcohol.
But does look like you may need new pads.

HillRider

Those "gaps" are intended to allow water to escape in wet weather and to act a wear indicators. When they disappear, replace the pads.

What type of brakes do you have? Cantilevers and V-brakes are notorious for squealing and there is no certain cure.

sbslider

I have cleaned the rim, but not with alcohol. I will try it though. It is only the front brake, and I do very little with the front wheel in terms of handling it, so I am a bit skeptical that is the cause.

Original question still in play, What I am wondering is do those gaps help with squeaking?

sbslider

good question, they are cantilever brakes. They look alot like these:

xenologer

Related story
I've had a customer bring a bike in complaining of front brake squealing.
I adjust toe in, clean rims, etc. I test ride it, no probs. customer tries it, complains about noise.
Explanation/lesson learned:
when I rode it, I assertively used the front brake. the customer only used very light pressure (fear of endo perhaps?)
having the brake drag on the rims with very light pressure makes plenty of noise, the extended braking distance allows vibrations to build to audible levels.
ended up readjustng, this time testing using the (poor) braking habits that the customer used.

Well, i guess in summary, braking technique can be just as big a factor as brake adjustment.
my own brakes are silent when I use them; but some can be noisey if I let a friend try it.

Practice hard endo stops, see if that fixes the problem. When you stop fast the brakes dont have time to squeal; plus toe-in tends to weaken stopping power.

sbslider

Mine tend to squeak only when I brake with moderate or more pressure. Hard stops are REALLY loud. Kind of good if someone cuts me off and I want to get there attention, but annoying in general. Not sure I have ever tried to brake so hard I might go over the bars, I will try that out in a "controlled" way.

dsbrantjr

Do your front brakes have a stem or headset mounted cable stop/hanger? If so you might be experiencing "brake shudder" due to flex in the steerer. A fork crown mount cable hanger may help quiet it down. I like the Specialized tricross hanger. Toeing-in the pads may help, but it reduces braking efficiency and the squeal will return when the pads wear the toe-in away.

FBinNY 

Brake squeal ultimately is the result of lack of rigidity in the brakes. As you apply the brakes the rim's forward motion pushes the shoes forward. Since the pivots are back from the braking surface, this cause the pads to rotate slightly, bringing the toes out and heels in. When the shoes can't move forward any more and a more slippery area of the rim comes along the pad slips back to the original position. This happens at high speed causing a vibration which can be felt as a shuddering, or heard as a squeal.

This only happens at moderate braking pressure because as you brake harder, the shoes are forced flat to the rim and cannot rotate.

The cure is to clean the rim and shoe surface so the braking action is more uniform. Toe-in helps up to a point when it's done so the rotating motion brings the shoe flat at moderate braking force. Otherwise, anything you can do to increase overall rigidity helps. Adding a shim to eliminate any free play of the brake on the post, using a stiff grease between the bushing and post.

Long heeled posts (Kool Stop design) help because they resist the rotation. In very tough cases I've had some success filing away the rear corner of the shoe into a ski tip so there wouldn't be a corner to dig in as the pad rotated, but this has the drawback of worsening wet performance, ad does excess toe-in.

FWIW, my canti commuter has brake squeal when it's humid, but it clears up within a day or two. In the meantime I think of it as an automatic horn which isn't all that bad in city traffic.

If all else fails and the squealing is really bothering you, a brake booster horseshoe can do a great job curing it.

sbslider

So I got to try out my new brake pads, they are much improved. However, at very hard breaking, they still squal a bit. I can live with that, but I will try cleaning the rims with alcohol, as well as possibly re-greasing the brakes as mentioned in another surly cross check front brake squeal thread I found.

As afar as the cable stop goes, it is very similar to this picture
https://https://www.flickr.com/photos/thedjneight/2249425531/

pierce

the right amount of toe-in is the main weapon against squeal with conventional rim brakes. if the pads are glazed, I'll rough them up with some sandpaper to remove the glaze

HillRider

Cantilever and V-brakes are notoriously noisy and my experience mirrors yours. They are loudest under hard braking, not at modest braking pressure as FBinNY asserts. I tried everything, including substituting road brake pads and holders for the longer Canti/v-brake holders. They helped but weren't 100% effective.

Looigi

I clean the brake tracks with a green kitchen Scotchbrite pad. It can help to do the same to the face of the pads.

sbslider

Cleaning the rims did not make a noticeable improvement in my case, the biggest factor was just replacing the pads. One thing I have learned via the posts above and other things I gleaned last night is there are many different contributors to squeaky brakes, and sometimes no matter what you try nothing seems to help. Glad in my case just new pads did the trick.

AJ08

In my case I didn't have this problem until I installed new front pads. The squeeking is much worse if it's wet out or when applying lighter pressure to the brakes. They make no noise if I brake hard though. The front brakes are all salmon and I wonder if going with a mix of salmon and black would make a difference. It's amazing how loud they can be.

pierce

sounds like you need to adjust for a bit more toe-in. the forward edge of the brakes should touch first, when the rearward edges are still about 1/8" out, give or take. when the brakes flex under the force of braking, it pulls the shoes forward which takes out this toe-in. if there's no toe-in to start with, then they oscillate and make the loud squeal.

also cleaning any old brake pad material off the rim, I use paint thinner or alcohol on a cloth rag.

fietsbob

Noting the picture you Posted, a plain Post type,

Try Kool Stop Eagle Claw brake pads , when you install them the raised Plough tail helps clear debris
and will give a bit of toe in as you tighten the nut on the shaft clamp, reduce the squealing you find..

Salmon is good for wet weather , but in Santa Barbara Cal,
that is not so much a weather constant, Black KS may do.

Al1943

Koolstop salmon pads work well in dry climates too, though they are especially good in wet climates.

sbslider

Yeah, it"s been a couple months since the OP, I did get salmon kool stops for the front, they were still squeaky. Then I adjusted them properly and they work great. Maybe the old pads would have also, but I needed new ones anyway. Lesson learned: pad adjustment is critical to brake performance, kool stops work well when adjusted properly. One would think that SB is not a we climate, but even when it does not rain, we get lots of coastal fog in the spring/summer and you can get pretty wet riding in the fog as well.

I did not find that cleaning the rims made a difference as far as squeaking goes, but it does as far as performance wet goes.

AJ08

Thanks for the mounting tips but I'm just not skilled enough to do it. I tried for quite a while and just getting the brakes aligned was hard enough but getting them so the front part touches just a bit before the back is well beyond my skill level. I think I'm just destined to have noisy brakes. I'll bring it up the next time I have my bike in for service if it's still a problem.

sbslider

Try this trick I learned. Tape a nickel to the back of the pad, then place the pad against the rip where you want it to touch, and tighten. It is still a bit tricky, but providing the spacer during adjustment has worked well for me getting brakes that don't squeal. Maybe something thinner than a nickel is better (penny or dime) but the nickel worked for me.

fietsbob

well you do get the attention of the other users of the MUP , with a little brake squeal.

HvPnyrs

What I have done for years (Ok, Ok, more like decades) is to use a business card, thickness is easily adjustable by the number of times the card is folded, one can also use a playing card if you should need more thickness (although I never have needed more than a business card).
Once the desired thickness is achieved bend the card into a *U* shape (like the shackle of a u-lock) then slide the ends of the *U* under the rear facing ends of both brake pads, on either side of the rim, then secure in place with a THIRD HAND TOOL (cheapest method).
Although I have found that a Fourth Hand Tool REALLY helps speed up and simplify the process. I have not used a third hand tool in adjusting my brake pads in many years.

xenologer

mom's bike, her tendancy to only weakly drag the brakes instead of actually using power leads to excessive chatter. toe-in, sanding, cleaning all fail. Final solution: replace brake arms with higher quality ones; pivots are machined to higher tolerance; leave less wiggle room for vibration.