Bicycle Mechanics - How do you properly "toe-in" Brake pads???

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jxpowers
11-24-12, 05:15 AM
So i have this annoying squeal on my brakes, I bought 2 pairs of kool stop salmons and they have been squealing for about a week now.
I have tried to sand the rims, then sand the pads, then i washed the sand off. All 3 times they squealed so i tried to add a little lube on the pads that worked but that was a short term solution since the squeal came back.
Then I read about toeing in the pads, which i think means to make it so that the front end of the brakes touch the rims before the back right? i read that this defiantly stops the brakes squeal for me it hasent worked
so can anyone tell me what else i can do, i have defiantly toed them in because i can visually see that when I brake the fronts touch first.
Also its only the front ones that squeal not the back ones and they only squeal when im riding at a decent speed lastly im positive none of the brake pads are touching the tyre
Please help thanks
rydabent
11-24-12, 05:49 AM
Toe in means the pads are not as close in the back where the rim first enters the pad. What I do is take a thin washer or a thin dime and put it under the back of the pad and seat the bolt. It ends up that the pad does have more clearance at the back, but not as much as the dime or washer. This has worked well for me.
jxpowers
11-24-12, 05:55 AM
Yeah ive just tried that way where you put a piece of card at the back and then tighten it and its still squealing, so i washed the rims and the pads again and give it a little sand still squealing a little
HillRider
11-24-12, 06:49 AM
What type and make/model brake are you dealing with?
reptilezs
11-24-12, 06:56 AM
try a toe out
xenologer
11-24-12, 07:09 AM
So i have this annoying squeal on my brakes, I bought 2 pairs of kool stop salmons and they have been squealing for about a week now.
I have tried to sand the rims, then sand the pads, then i washed the sand off. All 3 times they squealed so i tried to add a little lube on the pads that worked but that was a short term solution since the squeal came back.
Then I read about toeing in the pads, which i think means to make it so that the front end of the brakes touch the rims before the back right? i read that this defiantly stops the brakes squeal for me it hasent worked
so can anyone tell me what else i can do, i have defiantly toed them in because i can visually see that when I brake the fronts touch first.
Also its only the front ones that squeal not the back ones and they only squeal when im riding at a decent speed lastly im positive none of the brake pads are touching the tyre
Please help thanks
Yeah, so putting lubricant on your brake pads is very bad.
Don't Ever Do That Again!
See, brakes slow you down by using friction against the rim to slow its rotation. Lubricants reduce friction. No friction means no brakes.
You need to clean your pads and rims very thuroughly to remove all traces of lube contaiminant before proceeding..
gummy residue of lube mixed with dirt and stuff can itself become a source of squealing
Since this is only the front brake that does it.... when you use the front brake are you only gingerly dragging the brake? or are you doing full handed endo stops?
I find that grabbing the front brake hard, deccelerates the bike faster than sqeal/vibrations can begin to resonate audibly.
Strong decceleration plus no sounds? That's a win-win for me. Practice doing controlled endos.
Or you can keep toe-ing the pads in, but that weakens the braking power....
The former solution works with how I ride, your methods may differ.
First of all, NEVER lubricate the braking surface. You want maximum friction, because that's what you depend on to stop the bike.
Now, before you can manage squealing you need to understand it's cause.
When you apply the brakes the motion of the rim pushes the pad forward with the same force as the braking force. This causes the brake arm to twist so the heel of the shoe digs in momentarily increasing the brake force, until it slips back. This happens at high speed causing a vibration you hear as a squeal. As you apply the brakes harder you'll push the pad flat again, so squealing tends to happen only at moderate brake pressure.
Over time the shoes will wear, adapting to the twist and the squeal will go away by itself. But if you're impatient you can speed up the process with toe in. The amount of toe-in needed depends on the rigidity of your brake and the friction properties of your pad material.
Good pads (high friction) require more toe-in since they create more braking force (and reaction twist) than crappy pads. Likewise with less rigid brake calipers since they twist more. You can see this effect and get an idea of how much toe-in you want by gently applying the brakes while pushing the bike forward, and seeing how far the front of the shoes spread. Toe-in by the same amount or very slightly more, so the natural twist brings the shoe flat.
You can also cure squeal by removing the back corner, so it can't dig in and vibrate. File a shallow angle into the back 1/4" or so, making sort of a ski tip curve. Warning, don't do this if you ride in the rain since it will worsen wet performance.
Toe-in is good. What also may help brake squeal is to clean the rim brake track. I use a green Scotchbrite kitchen scrubber which is mildly abrasive and cuts through the caked on gunk. It can also be helpful to clean the surface of the brake pads if they're contaminated.
fietsbob
11-24-12, 10:22 AM
What type and make/model brake are you dealing with?
how you toe in a brake shoe depends on how the shoe is attached to the brake.
bend the brake, bend the post in the shoe holder,
buying TRP 'adjust in place' plain post brake pads/holders.
wedge lever under the nut? stack of concave.convex washers [v brakes]
all are slightly different techniques .. depending on the brake installed..
jxpowers
11-25-12, 02:08 PM
I have the kool stop brake pads the really long ones
AlphaDogg
11-25-12, 02:26 PM
You put lubricant on brake pads that you expect to actually stop your bike? :rolleyes:
Some brakes just squeal in my experience. Toeing you pads in often helps a LOT. Can you post a picture of how your pads are set up?
ksisler
11-25-12, 02:39 PM
Yeah ive just tried that way where you put a piece of card at the back and then tighten it and its still squealing, so i washed the rims and the pads again and give it a little sand still squealing a little
A piece of card stock is likley not what rydabent meant. Card is not thick enough. Use a dime like he recommended. If no dime, then a popsickle stick. Something 1/16th inch or just a bit thicker.
Seconds; if you post the specific brakes you have and maybe even a picture of them installed, help can be more specific.
jxpowers
11-25-12, 02:58 PM
A piece of card stock is likley not what rydabent meant. Card is not thick enough. Use a dime like he recommended. If no dime, then a popsickle stick. Something 1/16th inch or just a bit thicker.
Seconds; if you post the specific brakes you have and maybe even a picture of them installed, help can be more specific.
http://www.amazon.co.uk/Kool-Stop-Mountain-Threaded-Linear-Salmon/dp/B001CJZ0Q2/ref=sr_1_3?ie=UTF8&qid=1353880249&sr=8-3
here are the brakes i have
i dont see how posting pictures would work because the suspensions are in the way and you wouldnt be able to see the "toe-in". and what other ways are there to set up brakes? I know how to align them to the rim ect
The card i used is like a business card folded up 4 times
Also ive read in quite a few places on this forum and in other places that lube does help with squealing and it did but as i said it was only short term and it hardly effected braking
Madtown Bob
11-25-12, 04:00 PM
I use a somewhat thick and wide rubber band to provide a "toe-in" when I’m adjusting my brake pads. This idea is similar to the dime suggestion. If you get the height and toe-in right, I wouldn’t worry about it. I believe the squeal will go away after a while.
http://www.amazon.co.uk/Kool-Stop-Mountain-Threaded-Linear-Salmon/dp/B001CJZ0Q2/ref=sr_1_3?ie=UTF8&qid=1353880249&sr=8-3
here are the brakes i have
Do you see that raised snowplow on the back tip of the shoe. That's to help you set the right amount of toe-in. Unfortunately, until it wears off, it's a major cause of squealing. Take the shoes off and file or grind the plow off flush to the rest of the shoe, then go a bit farther and take it down
so it won't touch the rim when the shoes are flat. That will allow the shoe to twist (as it will) yet not dig in.
When the shoes are prepared, mount them using a dime trapped just forward of the back end as a toe-in gauge.
531phile
11-25-12, 09:46 PM
Try toe in one side and toe out the other side. Works when all else fails.
3alarmer
11-25-12, 10:41 PM
You put your right toe in,
You put your right toe out,
You put your right toe in,
And you shake it all about,
You do the hokey pokey
and you turn yourself around
That what it's all about.http://www.runemasterstudios.com/graemlins/images/bunnydance.gif
“toe-in” is a misnomer. From an engineering point of view, it is really “heel-in”. Why? If you are the brake shoe and the surface is moving under you very rapidly, would you use your heel or toe first? If you responded with your toe, what do you think will happen should it catch? Maybe a broken ankle? It is an issue of reference. From the bikes perspective the front of the bike is considered the leading part during motion, but the brake is at the top of the wheel where the wheel is rotation toward the direction of the bike. It is going twice as fast as you are when you are riding (remember the hub is going the same speed and the tire on the road has 0 velocity with good grip).
So what is commonly referred to as “toe-in” is really “heel-in and it is not the leading part of the shoe but the trailing part. This statement is contrary to prevailing discussions, but there was a time when the right brake lever controlled the front brake too, the constant is change.
Another consideration for “squealing” is the slack in the mounting of the calipers. If there is a slight play in the mounting, it will allow for the oscillation of movement which is the action that generates the sound. Its frequency is directly related to the harmonics of the oscillation. So the contributing factors are stiffness of the caliper arm, mounting “tightness”, the coefficient of friction between the pad and the braking surface creating the dynamic action of stick and release at a high frequency.
Sometimes the operational dynamic range of the offending system exceeds the variable adjustment of contributing components of the configuration. In other words there is not one solution or there might not be an easy solution. There may one or two adjustments that are outside of the range but not always.
fietsbob
11-26-12, 08:59 AM
As the top of a wheel rolling you forward, is rotating forward, 'toe' is the trailing end of the brake pad.
Also, get an emery board and put it between the pad and the rim. Lightly apply brake and spin the wheel.
The surface of the rim gets glazed with the brake pad material sometimes, and is a source of squeal/poor performance.
My brakes will squeal in the rain - all of them. Disc and rim alike. Personally I suspect it happens most when things get ' too' clean, cause it goes away as the brakes get used more and contaminants get dried to the surfaces.
Jagwire makes an alignment tool just for this if you think a specialized tool might help, but all the spacer suggestions offered so far are just as effective.
ksisler
11-29-12, 05:51 PM
http://www.amazon.co.uk/Kool-Stop-Mountain-Threaded-Linear-Salmon/dp/B001CJZ0Q2/ref=sr_1_3?ie=UTF8&qid=1353880249&sr=8-3
here are the brakes i have i dont see how posting pictures would work because the suspensions are in the way and you wouldnt be able to see the "toe-in". and what other ways are there to set up brakes? I know how to align them to the rim ect The card i used is like a business card folded up 4 times. Also ive read in quite a few places on this forum and in other places that lube does help with squealing and it did but as i said it was only short term and it hardly effected braking
That is an ad for the brake-pads. Useless to solving the issue. When I said "picture of your brakes" I was meaning of your brakes as installed on your bike, and taken from an angle that would be relevant.
Yes a standard business card folded 4x (now you tell us) is getting close to the right thickness.
rydabent
11-30-12, 07:30 AM
As several have mentioned, cleaning the braking surface of the rim helps, since you still might get squeal with proper toe in. I also remove the wheels and lightly sand the brake pad material to remove the glaze, and then wash away all the grit and dirt before putting the wheel back on.
jxpowers
12-01-12, 07:59 AM
I couldnt exactly fix it but....
i changed the rims to one where the grooves on the rim are finer and smaller, this stopped the squeal immediately
jxpowers
12-01-12, 08:10 AM
As several have mentioned, cleaning the braking surface of the rim helps, since you still might get squeal with proper toe in. I also remove the wheels and lightly sand the brake pad material to remove the glaze, and then wash away all the grit and dirt before putting the wheel back on.
my first post mentioned that i did that...
FrenchFit
12-01-12, 08:40 AM
There could be a secondary problem, like a loose pivot bolt. If the brakes don't squeal at light initial contact but do under pressure it may mean the arms or pads are flexing outward as torqued against the rim..though chattering is what I'd suspect to see. I'd put the bike on a stand, spin the wheel, and watch closely as brake pressure is applied - look for any secondary movement of any of the brake components.
jxpowers
12-02-12, 09:34 AM
There could be a secondary problem, like a loose pivot bolt. If the brakes don't squeal at light initial contact but do under pressure it may mean the arms or pads are flexing outward as torqued against the rim..though chattering is what I'd suspect to see. I'd put the bike on a stand, spin the wheel, and watch closely as brake pressure is applied - look for any secondary movement of any of the brake components.
I think it was the pads or the rims
i had the stock brake pads before i put the kool stops on and they were fine and never squeaked
vredstein
12-04-12, 03:40 AM
I think it was the pads or the rims
i had the stock brake pads before i put the kool stops on and they were fine and never squeaked
I think the lesson here is that there's not a single cause responsible for all brake squealing. But toe-in the the most common cure, fixes most problems. Sometimes it's the pad, sometimes it's the rim. Sometimes it's a particular combination of pad and rim. I use those same pads on two of my bikes. There's a bit of noise, but I think it's because the pads material is very grippy. They have a lot of surface area, have a curve that matches the rim, and NEVER trap grit. I've never had grit or slivers of aluminum get imbedded in them. If I used stock shimano black pads, which are harder, they don't squeal, but make hushed, abrasive sounds, don't stop as well, and get grit and slivers of aluminum imbedding them, which creates that grinding sound.
jxpowers
12-04-12, 05:22 AM
There could be a secondary problem, like a loose pivot bolt. If the brakes don't squeal at light initial contact but do under pressure it may mean the arms or pads are flexing outward as torqued against the rim..though chattering is what I'd suspect to see. I'd put the bike on a stand, spin the wheel, and watch closely as brake pressure is applied - look for any secondary movement of any of the brake components.
I checked out the brake arm and you were right , they are slightly wobbly, the back brake arms dont move at all but the front ones wobble a tiny bit, tightening them dosent seem to fix it as the washer dosent make contact with the brake arm because theres this small gold tube inside the brake arm, cant really explain it,
but ive seemed to have fix it with "toe out" . might have to invest in new v brakes?
Squares17
12-04-12, 12:29 PM
I have Kool Stop Salmons on my commuter and have roughly 300 miles on them. I bought them because of all the awesome reviews, but about a week after installation, I was about to throw them away. I worked on those things (toeing, sanding, cussing) for hours and finally just gave up and let them squeal. I think that they have finally gotten all the screaming out of their system, and I just assume it took some time to wear them down to accomplish this. I recently put a set of Kool Stop dual compound (salmon and black) on the rear of my old hardtail, and it's the exact same story. I feel like maybe you just have to put up with the noise for a while in exchange for the performance?? They really do a great job, but that squall can be quite frustrating.
I checked out the brake arm and you were right , they are slightly wobbly, the back brake arms dont move at all but the front ones wobble a tiny bit, tightening them dosent seem to fix it as the washer dosent make contact with the brake arm because theres this small gold tube inside the brake arm, cant really explain it,
but ive seemed to have fix it with "toe out" . might have to invest in new v brakes?
That brass tube is what allows you to use a single bolt to hold the brake arm in place while still allowing it move freely, unlike on a sidepull where locknuts are required. You crank up the bolt and and it bears on the brass sleeve instead of the brake arm. You can probably use a file to trim it down a little to reduce the play, but you'll need to use some trial and error to avoid overdoing it, at which point your brake will be junk. Also, a little slop along the axis of the bolt isn't so much an issue as radial play that allows the arm to flop around in any direction rather than along the sleeve. If you can hold the bottom of the arm with your thumb and wiggle the top of it back and forth with your fingers, the brake is pretty much shot.
The good news is that even rooted V-brakes generally work a whole lot better than cheap sidepulls.
Chesha Neko
12-07-12, 12:08 AM
I switched to SwissStop pads. No squeak.
Sixty Fiver
12-07-12, 12:16 AM
We still don't know what kind of brakes we are dealing with... some are notorious for squealing no matter what kind of brake pad you use, some can be fixed by changing the lever (XTR dual pivots), and the old Avid Shorty brakes are nearly irredeemable when it comes to squealing issues.
Kool Stop salmon pads usually solve squealing issues although mine will squawk a little when it is very cold... the dual compound pads tend to be quieter in colder conditions.
Sixty Fiver
12-07-12, 12:17 AM
My super sophisticated professional toe in tool cost me ten cents... :)
Clarabelle
12-07-12, 12:46 AM
You put your right toe in,
You put your right toe out,
You put your right toe in,
And you shake it all about,
You do the hokey pokey
and you turn yourself around
That what it's all about.http://www.runemasterstudios.com/graemlins/images/bunnydance.gif
My kinda guy.
noglider
12-07-12, 08:22 AM
Believe it or not, lubing the brake surface does not necessarily worsen braking. I had to fix a local kid's department store bike. The pads were very close to the rim and left no room for toe in. The brakes were of such poor quality that if I loosened the cable, the brakes would not work adequately. But the brakes were squealing. As a last resort, I oiled the brake surface. I think the pads absorbed the oil and softened them. They removed the oil from the rim. With the new texture in the pads, the resonant frequency was changed, and there was no more audible squealing.
Again, it was a last resort, done out of desperation. It worked better than I had expected. The brakes ended up working quite well.
TimeTravel_0
12-07-12, 10:29 AM
you couldnt have rearranged the washers for clearance? or switched to thinner pads? or increased spring tension when you decrease cable tension?
greasing up rims...yeah, I cant get down with that. thats just sloppy wrenching and probably just a temporary band-aid.
I like to file down the leading edge of the shoe, which is the back end when mounted as toe in doesn't always quiet things down. As mentioned type of pad, rim etc. all come into play here.
My super sophisticated professional toe in tool cost me ten cents... :)
and you got a full refund after using it!
TimeTravel_0
12-10-12, 07:31 AM
I use a tacx brake pad tuner, btw.
good tool.
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