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Whether your bike has rim or disc brakes you don’t have to put up with them squealing. Here are some common causes of screechy brakes and how to sort them

You’re cycling along a quiet country lane enjoying the view and the hum of tyres on tarmac, only for the peace and quiet to be shattered by a loud squealing sound as soon as you pull on the brake levers. 

There’s nothing more annoying than squealing brakes. Any unwanted noise from the bike when you’re riding is immensely irritating, but noisy brakes are probably at the top of the list of annoyances.

Related: 9 top tips for setting up your new road bike

Why all the noise?

Unfortunately, squealing brakes can be quite common. Besides the annoying noise, squealing brakes can also mean decreased braking performance. Different combinations of braking surface and brake pad can play a part and the conditions can influence the noise your brakes may or may not make.

SLorencePhoto Giant TCR Advanced SL action   - 12.jpg

SLorencePhoto Giant TCR Advanced SL action - 12.jpg

“Squealing brakes can occur for several reasons, usually, if you have some grease or oil on the brake pad, rotor or wheel rim or the contact between the braking surfaces is misaligned. New brake pads also need to bed-in for optimum performance,” says Shimano. 

While contamination is one cause, vibration is another and can indicate poorly set-up brakes. We’ll go through a few of the most common solutions and remedies for eradicating noisy brakes with rim and disc brakes. 

Rim brakes

The first thing you want to do with rim brakes is to ensure the brake calipers and the braking surfaces of the rim and the brake blocks are thoroughly cleaned and in good working condition. Also, check that all bolts securing the caliper to the frame and the brake blocks to the calipers are securely tightened. Any loose parts can cause unwanted brake noise.

Colnago V1-r brakes - front

Colnago V1-r brakes - front

Often the cause of brake squeal is contamination, caused by enthusiastic chain lubing or oil picked up riding on the road in wet conditions with lots of puddles. So make sure the rims are cleaned thoroughly with a degreaser to remove any residue oil. There are many brake cleaners on the market that can help to ensure the braking surfaces are in tip top condition.

The noise might be caused by brake blocks in poor condition, being glazed over or unevenly worn. Pick any small pieces of grit out of the brake blocks and use sandpaper or a file to smooth away the top layer especially if they are glazed over. Are the blocks worn out? Then they need replacing - most brake blocks have wear indicators. If the brake blocks are worn unevenly then that can be a sign they are not set up properly.

As well as inspecting the condition of the brake blocks, also pay attention to the rims. Most aluminium rims have a machined surface that is designed to provide a rough surface to provide good braking performance. A buildup of dirt or a worn rim can be detrimental to braking efficiency, so give them a scrub to remove any residue dirt.

If a good clean doesn’t solve the noise, the other likely cause is vibration caused by a poorly set up brake. 

BBB Tech Stop Pads on bike

BBB Tech Stop Pads on bike

“If your brakes judder and squeal when you apply the brake then there's a good chance your brakes aren't meeting the rim or the rotor correctly. Apply the brake and take a look at how the surfaces come together, then, with the brake still applied, loosen the mounting bolt(s) slightly and, if necessary, reposition the pad or the disc brake mount to ensure an accurate connection point,” says Shimano. 

One popular solution is to toe-in the pads. Normally brake blocks are installed so they are parallel with the rims. Toe-in requires setting the blocks so that the front section contacts the rim first. You can buy a special tool to do this, or a piece of cardboard of a few millimetres thickness works well - a folded over business card does the job. Loosen the brake blocks, push the piece of card behind the rear of the block, and tighten the bolt.

BBB Tech Stop brake pads.jpg

BBB Tech Stop brake pads.jpg

Sometimes buying new brake blocks is the best solution, especially if they are badly worn. Rim and brake block combination can be a factor. There are many different brake block compounds available, designed for different rim materials, conditions and demands. Sometimes changing the type of brake blocks can solve the issue of noisy brakes. 

Reviews: Brake pads & spares

Other causes of brake squeal can be due to any play in the braking system or even the hub bearings. A small amount of play in the wheel bearings can also contribute to squealing brakes. Some brake calipers are light and flexy and this can contribute to unwanted play as the brake block contacts the surface of the rim.

Disc brakes

The causes of noisy disc brakes are much the same as it is for rim brakes. Again, the most common cause of disc brakes squealing is due to contamination of the rotor or pads. That’s why you have to be very careful when using spray lubricants on a bicycle with disc brakes, probably best to avoid using spray lubes anywhere near a bike with disc brakes. 

Shimano road discs - front disc and calliper

Shimano road discs - front disc and calliper

“Cleaning your rotors or wheel rims regularly with a specific (oil-free) disc brake degreaser is a good way to avoid squealing brakes. Cleaning your pads too can help quieten things down - you can try some sandpaper or grinding the pads - but if the grease has soaked through the pad, you might need to replace them. Don't use a degreaser or chemicals on brake pads, though,” says Shimano.

First, you want to ensure all the braking components and surfaces are spotlessly clean. You can buy dedicated disc brake cleaners and sometimes this can be an instant fix. An alternative and common remedy is isopropyl alcohol. Use it to clean the disc rotors with a small rag. It’s easier to remove the rotor to do this, but you can do it while attached to the wheel.

vx801c-disc-pad-organic (1).jpg

vx801c-disc-pad-organic (1).jpg

The disc pads can also become contaminated. Unlike rim brake blocks, it’s not quite as easy to clean pads if they are contaminated, largely because you have to completely remove them from the bike in the first place. Sometimes a bit of scrubbing with sandpaper can remove the top layer of residue and any glazing that has occurred, and this can often work reasonably well, but if it's really bad, you might have to buy new pads. Some people say you can bake brake pads in the oven to cure this problem, but it's not something we've ever tried so can't vouch for its success rate.

Related: All you need to know about replacing disc brake pads 

The bedding in process with disc brakes is very different to rim brakes and is worth doing properly following installation of new pads. It can make a big difference to the performance. The pads will leave small deposits of material on the disc rotor and the best way to bed in pads is to ride along the street at a decent speed and pull firmly on the brake levers. Repeat this procedure a few time to ensure the discs are adequately bedded in.

sven nys shimano disc brakes 04

sven nys shimano disc brakes 04

The other cause of noise with disc brakes can be down to the caliper not being perfectly lined up with the rotor, or due to a slight bend in the rotor. Disc rotors can bend quite easily, which is why you have to be careful when travelling with the bike in the car or plane for this reason. They can be easily straightened with careful use of an adjustable spanner or a professional tool if you’re feeling flush. 

To ensure the rotor is positioned evenly over the rotor, first loosen the two caliper bolts, then while squeezing the brake lever, tighten the bolts. Sometimes this works fine, but sometimes you might need to make some small adjustments by eye - the clearance between the rotor and brake pads is very minimal. You're aiming to have the caliper centrally positioned over the disc rotor with equal clearance either side.

Related: Everything you need to know about disc brakes

Hopefully, those steps will help alleviate your noisy brakes. Do you have any top tips that you swear by for fixing squealing brakes?

David has worked on the road.cc tech team since July 2012. Previously he was editor of Bikemagic.com and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds.

46 comments

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sizbut [37 posts] 2 years ago
2 likes

A small dab of copper anti-seize between the piston and disk pad cured the wet weather squeal on my TRP Sprye brakes. Naturally be very cautious to ensure its just a little so that none gets onto the front of the disk pad.

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bendertherobot [1522 posts] 2 years ago
0 likes

Mine are bad in the wet so I'll give that a go!

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muffies [81 posts] 2 years ago
0 likes

using centerline rotors decreased brake noise a lot for me. they only squeal if its raining hard with a lot of street stuff projecting on them - but even so, they stop squealing after 5-10s of constant braking (which clean them rather quickly)

 

night and day different with other rotors. other than that they'll basically always squeal at some point if things get really dirty outside.

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KiwiMike [1368 posts] 2 years ago
3 likes

"the best way to bed in pads is to ride along the street at a decent speed and pull firmly on the brake levers. Repeat this procedure a few time to ensure the discs are adequately bedded in"

 

The accepted wisdom here is that it's a bit more thorough than 'a few times'.

What you are trying to do is bake a thin layer of pad material onto the rotor, both sides, all the way round. Pads will not grip slick stainless steel well, and even a small gap will result in brake judder as the pads grip-slip-grip-slip- etc. This material transfer takes a lot of heat and consistent application over a short period of time.

 

Step 1: thoroughly sand rotors and pads with 200-grit sandpaper. Use different paper for each. Remove the rotors to do both sides properly. You want to get the rotor track areas totally scratched-up, no shiny at all. The pads, you just need to get a clean layer showing, unless you've soaked them in oil/lube, in which case spend the £5-10 on new pads and be More Careful next time. Clean both off with a proper disc brake cleaner, I've had success with the Bikehut one, others are available.

Step 2: replace rotors using Loctite (if they are bolt-on) and a torque wrench.

Step 3: Find a steep hill, smooth road and no cars.

Step 4: Get up to 20kph, then put the brakes on hard and hold them in one motion, but do not lock up or come to a stop - brake consistently close to the limit of traction - hence, do NOT try this on a gravelly, wet or mossy road. When you are almost stopped, speed up again to 20 and repeat, 10 times.

Step 4: Get up to 30kph, and repeat 5 times.

This might seem like overkill, and for sure some will think their brakes are burnt in after less effort. Much easier to do it properly, the first time, than have to reset the pads/rotors all over again when the pad material transfer onto the rotor hasn't gone right.

 

 

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mingmong [312 posts] 2 years ago
0 likes

New brakes / pads?

 

Drag your disk brakes down a big hill to get them hot.  Stop and tip your water bottle on them.

 

Works for me. 

 

 

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DaveE128 [996 posts] 2 years ago
3 likes

I would have thought that the bedding in process is more about wearing the rotor and pads to match each other so that there is uniform pressure across the mating area, rather than some kind of material transfer.

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crazy-legs [1014 posts] 2 years ago
3 likes

Many years ago a guy brought his bike into the shop I worked at complaining about his brakes not working.

We looked at the bike (some commuter job which was filthy).

Us: "well you need to clean up your rims, they're covered in muck, that won't be helping"

Customer: "oh, that's oil, I put that on to stop them squealing"

Us: "right, that'd be why your brakes aren't working then..."

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wycombewheeler [1331 posts] 2 years ago
0 likes
crazy-legs wrote:

Many years ago a guy brought his bike into the shop I worked at complaining about his brakes not working.

We looked at the bike (some commuter job which was filthy).

Us: "well you need to clean up your rims, they're covered in muck, that won't be helping"

Customer: "oh, that's oil, I put that on to stop them squealing"

Us: "right, that'd be why your brakes aren't working then..."

I did once have a pedestrian tell me my bike needed oil because it was squealing when I used the brakes.

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KiwiMike [1368 posts] 2 years ago
0 likes
DaveE128 wrote:

I would have thought that the bedding in process is more about wearing the rotor and pads to match each other so that there is uniform pressure across the mating area, rather than some kind of material transfer.

 

Nope, it's totally about the material. New rotors and pads are usually perfectly smooth and aligned, but if the rotor is slick steel, they'll be pretty rubbish.

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kylemalco [39 posts] 2 years ago
0 likes

Squeal brakes are the bike's way of telling you too lose weight

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Dibbs [4 posts] 2 years ago
2 likes
DaveE128 wrote:

I would have thought that the bedding in process is more about wearing the rotor and pads to match each other so that there is uniform pressure across the mating area, rather than some kind of material transfer.

I agree, any  of this wonder material deposited on the disc's would be ground off by the first splash of the grinding paste they call mud round here. It's more about getting the pad surface to match the minute grooves in the disc surface.

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StraelGuy [1445 posts] 2 years ago
1 like

I agree with you Dibbs. If you look at a used pad, there's a silver metallic sheen on the surface which suggests that any deposition of one material onto the other would involve stainless steel embedding slightly in the pad material, not the other way around. 

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urbane [98 posts] 2 years ago
0 likes

My solutions for rim brakes:

  • Have rigid wheels which rarely require spoke adjustment and have hard wearing rims, even some Mavic rims are rubbish.
  • Use a battery powered wheel cleaning brush from ALDI, with decent soaked-in bicycle cleaner, to scrub off rim gunk far better/faster than hand cleaning can, this can really help with some stubborn squealing.
  • Get brake pads up/down and left/right aligned flat in the centre of the rim, never "toe in", adjust tension spring(s) to ensure both pads kiss the rim at the same time, then tighen up pads hard while braked hard on the rim via an adjustable clamp on the brake lever.  It's far better to use slide-in brake pads to make these alignments rare.
  • Sometimes just shaving/sanding the pad surface can help, this is easy with slide-in pads.
  • Always (re)clean rims when external lube may have got to the rim or brake pads.
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BertYardbrush [60 posts] 2 years ago
0 likes

Clean your rims with lighter fluid.

Degreases anything, also good for removing label ahesive residue from shiny surfaces.

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Geraldaut [59 posts] 2 years ago
0 likes

I would also like to know how to stop my disc-braked front wheel from wobbling while braking. The wheel seems true, also the disc. I re-adjusted the rotor several times (it is a model with 6 screws). It gets a bit better but wobbles still a bit under heavy breaking, very much so at light braking at low speed...

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JoshCroxton1 [32 posts] 2 years ago
0 likes

For contaminated pads.. blow torch them to burn up the oils, grit etc but not for too long that the pad itself glows hot.

Melting point of the oil, salt and all other grime that causes the squeal is lower than the melting point of the pad itself. I've done this 3 times on the same pads on a very winter-abused commuter with Shimano BR875's and it works a treat. 

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matthewn5 [1204 posts] 2 years ago
0 likes

A bit of vinegar wiped on the rim works for caliper brakes.

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BighugeMonkeysuit [18 posts] 2 years ago
0 likes

mingmong .. Surely that'll just warp you rotors? That's why you don't put hot pans straight in the sink after cooking with them. 

 

 

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Ratfink [200 posts] 2 years ago
0 likes

I've never managed to warp a saucepan doing that!

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mike the bike [1082 posts] 2 years ago
1 like

 

Pans? Cooking? Sinks?  Why would a man know about such things?

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Rich_cb [792 posts] 1 year ago
0 likes
Geraldaut wrote:

I would also like to know how to stop my disc-braked front wheel from wobbling while braking. The wheel seems true, also the disc. I re-adjusted the rotor several times (it is a model with 6 screws). It gets a bit better but wobbles still a bit under heavy breaking, very much so at light braking at low speed...

Have you checked your headset?

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surly_by_name [570 posts] 9 months ago
0 likes
KiwiMike wrote:

This might seem like overkill....

Yep, as well as (incorrectly) making discs sound like way too much hard work. 

For the most part, my experience matches the advice of the first responder on this thread http://singletrackworld.com/forum/topic/bedding-in-new-disc-brakes (essentially you will bed them in on first ride simply by act of braking, recognise that first half an hour or so braking will be a bit sub-optimal and take it easy, after which time it will improve).

 

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ClubSmed [692 posts] 9 months ago
1 like

Am I alone in liking the fact that my disc brakes squeal in the wet?

On my daily commute (through parks and along tow paths) there are a lot of blind bends where I "ding" my bell as I approach in order to alert anyone coming the other way. Quite a few of these blind bends are preceded by a steep downward slope.

In wet weather going down these slopes on the approach to the blind bends I need to take extra care to control my bike so do not like taking my hands off the handlebars/brakes to use my bell. Added to this, even if I did, my bell is not effective when covered in raindrops. This is not an issue though because when the wet weather comes my brakes make a sound loud enough to alert of my approach in these situations.

I was originally irritated by the squealing but after coming to the above realisation I love it.

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lork [37 posts] 9 months ago
0 likes
mike the bike wrote:

 

Pans? Cooking? Sinks?  Why would a man know about such things?

 

cause men know how to cook.

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hennie [31 posts] 9 months ago
1 like
lork wrote:
mike the bike wrote:

 

Pans? Cooking? Sinks?  Why would a man know about such things?

 

cause men know how to cook.

Mike knows that, it was a joke. I laughed anyway

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hennie [31 posts] 9 months ago
0 likes

.

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Rapha Nadal [847 posts] 9 months ago
0 likes

Don't use Swiss Stops on carbon rims.  Chuck them out & use something else.  Best, and most silent, thing I did.

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BehindTheBikesheds [2042 posts] 9 months ago
0 likes
Rapha Nadal wrote:

Don't use Swiss Stops on carbon rims.  Chuck them out & use something else.  Best, and most silent, thing I did.

Funny my Swiss Stops work just fine on my Campag Bora's, maybe you're using cheap shit rims or more likely simply you don't know how to set up brakes properly.

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sunnyape [42 posts] 9 months ago
0 likes
bendertherobot wrote:

Mine are bad in the wet so I'll give that a go!

Metallic disc brake pads tend to squeal more in the wet. If your rotors are compatible, try resin pads. They're generally quieter and have better initial bite, just not as long lasting.

As for cleaning disc brake pads, if mine get contaminated with degreaser or similar from cleaning the bike, I take the pads out, put a drop of dishwashing detergent on them, rub them against each other for a minute, then rinse with hot water. Works a treat.

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sunnyape [42 posts] 9 months ago
0 likes
Geraldaut wrote:

I would also like to know how to stop my disc-braked front wheel from wobbling while braking. The wheel seems true, also the disc. I re-adjusted the rotor several times (it is a model with 6 screws). It gets a bit better but wobbles still a bit under heavy breaking, very much so at light braking at low speed...

 

Might be headset being a bit loose. If I have too much play in mine, I get classic fork 'judder' when braking hard on discs.

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