disc brakes squeak

Grievesy

Active Member
had my bike a few months new, changed the tyres on it to some Gatorskins, when I put the wheels back on, all was fine, but I've noticed that when I pull the brake lever hard the brake squeals as if I'm torturing the disc. I'm guessing this just isn't aligned correctly? tried taking the wheel off and on again but it's still there. what's the best way to stop this?
 

glasgowcyclist

Charming but somewhat feckless
Location
Scotland
 

CXRAndy

Guru
Location
Lincs
had my bike a few months new, changed the tyres on it to some Gatorskins, when I put the wheels back on, all was fine, but I've noticed that when I pull the brake lever hard the brake squeals as if I'm torturing the disc. I'm guessing this just isn't aligned correctly? tried taking the wheel off and on again but it's still there. what's the best way to stop this?
Are these Shimano brake calipers for road bike with ceramic pistons
 

Kajjal

Veteran
Location
Wheely World
They might be contaminated with oil or similar. Best way to test is accelerate to speed and brake hard a few times. If after that they sound like you are strangling a turkey wipe the rotor with kitchen roll to see if any oily residue comes off. Dust and dirt is fine, it just gets burnt off.
 

CXRAndy

Guru
Location
Lincs
From my experience, this is mainly with Shimano brakes, but also Hope. Shimano do squeak alot, with either resin or sintered pads. It usually appears after the bike has got wet on a ride. Then an annoying squeal can be heard. Ive tried cleaning discs(alcohol and emery paper the surface) and pads, changing pads, all of which have a temporary cure.

I have come to the conclusion its the combination of Shimano discs and pads which seems to be the major cause. Shimano discs dont have as many cut out slots compared to some cheaper rotors. I've found using cheap rotors that the sound is almost eliminated. Braking performance doesnt seem to be impaired with using these more cut out rotors.

My experience with Hope is they hardly squeak or squeal after getting wet. They have better feel with having 4 pistons per caliper with slightly improved braking (larger pads area) performance over Shimano road calipers.
 

Kajjal

Veteran
Location
Wheely World
A bit more detail on my reply. First check pads are not worn down too far.

The biggest issue with disc brakes is normally contamination. This is when oil or similar gets into the pads, calliper and rotor. This means the brakes are being lubricated and the ability to brake is greatly compromised causing the screeching noise. You will get this with perfectly clean brakes in the wet but after a couple of pulls on the brakes it will go, except in heavier rain.

The solution to this if contaminated is to remove the old pads, these generally absorb oil like a sponge and cannot be cleaned. The with disk brake cleaner, thoroughly clean out the calliper and the rotors all over. If you use white kitchen roll once you stop getting black marks on the kitchen roll you know it is clean. Then fit new brake pads and get up to speed and brake hard a few times. This will fix it unless you have fluid leaking from the brakes.

Sources of the contamination are an over oiled dirty drive chain ( chain, cassette etc.), debris off the road, leaning the bike against something oily, touching the disks with oily hands, not being careful when oiling the chain etc / putting too much oil on the chain. Generally disc brakes do not get contaminated unless you are doing something to cause it or there is a build up over a long time, but you can be unlucky.
 
Location
Loch side.
perhaps @Yellow Saddle could tell the op what it does have to do with, for a chap with much knowledge you do sometimes come across a bit offhand, not sure whether you mean to or not.
Perhaps the OP can use the search function first and look at the reams of copy already written on the topic before asking the question. That is the correct etiquette, after all. This topic is frequently discussed so why should we go into it all again?

I can assure you my reply, like always, is sans emotion. My short comment was simply an attempt to stop the alignment nonsense right in its tracks. I was actually surprised that the usual suggestion to bleed the brakes hadn't popped up by then.

Once a proper search was done and the material studied, I'm always willing to answer further questions. Always have been, always will.
 

Gravity Aided

Legendary Member
Location
Land of Lincoln
I think that it is informative to hear about brake problems with disc brakes, as everyone seems to have different experiences and circumstances, and a one-size-fits -all approach to this sort of thing could lead to precious little new or enlightening information being presented by this section of the forum.
 

alicat

Legendary Member
Location
Staffs
Perhaps the OP can use the search function first and look at the reams of copy already written on the topic before asking the question. That is the correct etiquette, after all. This topic is frequently discussed so why should we go into it all again?

I can assure you my reply, like always, is sans emotion. My short comment was simply an attempt to stop the alignment nonsense right in its tracks. I was actually surprised that the usual suggestion to bleed the brakes hadn't popped up by then.

Once a proper search was done and the material studied, I'm always willing to answer further questions. Always have been, always will.
Or perhaps you could refrain from looking at this part of the forum if you're jaded and finding it hard to respond in a friendly and helpful way. :whistle:
 
Top Bottom