SuperMoto Junkie banner

1 - 8 of 8 Posts

·
Registered
Joined
·
131 Posts
Discussion Starter #1
Hey,

My front brake has started making a screaching noise when I use it... I have never had this on any of the bikes I've owned but this is the first with wavy disc's. Is this normal? Or is it something simple to fix. The brake works fine its just annoying more than anything!

Thanks

Rob
 

·
Registered
Joined
·
2,046 Posts
check the brake pads...even if they look like they got a lot of pad material left...sometimes the pads get a LARGER than normal chunk of metal incorporated into them when manufactured. (yes your brake pads have metal dust mixed in the pad material.

If the front rotor is shiny and smooth you will get that squeeling noise too...when smooth the pads have a harder time gripping the rotor and you have to use more pressure to get the brakes working like you would expect them to...this creates more heat...and vibration. (which is what creates that noise.) you can try to lightly sand the rotor in this scenario but usually a new rotor is in order.

CHANGE THE PADS IF YOU CHANGE THE ROTOR!!!!

good luck.
SDMOTARD
 

·
Registered
Joined
·
364 Posts
with cars (and I would assume bikes too) the squeal from when you apply the brakes is actually coming from where the metal backing plate of the pads contact the metal of the caliper (pistons, ends, ect...) and can be fixed easily. Yes, it is caused be pad to rotor contact but the noise we hear comes from the vibrations of the backing plate onto the caliper.
We would use a goldish colored anti-sieze compound (no idea what it is called, we got it from Brembo) and smear it between the metal contact points (DO NOT apply to pad material). This would always stop the noise, makes a mess if you are not careful but no more squeal.
Alot of guys wanted to run race brake pads on the street in the Ferrari and Porsche but didn't want the noise, this would stop it.

Good Luck, and keep in mind this was for cars but I assume it should work for bikes too.
 

·
Registered
Joined
·
1,377 Posts
We would use a goldish colored anti-sieze compound (no idea what it is called, we got it from Brembo) and smear it between the metal contact points (DO NOT apply to pad material).


plain old copper grease :thumbup:
 

·
Registered
Joined
·
131 Posts
Discussion Starter #6
its a brand new bike so i hope its not the rotor needing replacement! :O

I'm going to have a look tomorrow and see if there are obvious signs, and grease the backs
 

·
Registered
Joined
·
265 Posts
What bike is it? I have a 690 SMC and get the same thing when rolling to a stop sign slowly. Alot of these bikes have sintered pads and you will probably get that.
 

·
Registered
Joined
·
195 Posts
Most squealing is caused by harmonic vibration. The vibration can be caused by something as bad as a warped rotor or simple as greasy fingerprints on the rotor or pads. Even soap residue from washing will cause this. What happens is as the brake pads make contact the warp, hot spot, dirt, grease,soap etc- quickly grabs or shifts the pads in the caliper and the rub (much like drawing a bow across a violin string) creates a squeal.

Here are some things to check and do. If none of these work- replace pads and reset them. If that does not work live with it! First check the rotor for run out and warpage. It is best done on the wheel. If you find any run out- first loosen and retorque bolts in a star pattern to proper torque. Use a torque wrench! Clean the rotor with one of the following methods: ball hone (removes material-expensive tool), media blasting (removes much material, residue in buttons, expensive), scotchbrite along the grain (circular motion breaks ridges which can lead to more squeal- you are trying to clean crap from between ridges) followed by a light 1200 grit finish sand along the grain. Clean with brakecleaner and only handle with rubber gloves (use the dish wash gloves if needed and don't tell your wife). Pull the pads and using 600 grit paper on a sanding block- clean them up. If they are more than half worn, add some fluid to the resivour (worn pads/fluid lower situation allows piston to retract further from rotor with pad. Pad can then dance on rotor which causes high spots on pad which leads to noise).

I do this regularly (between each ride weekend) and have the best FTE KTM brakes that I know of. Also- do this whenever changing to new pads, especially if a different brand or commpound.

While there- you could check the caliperr mount interface with the fork lug and make sure both are flat and aligned ( a very common problem on american cars and I have seen it on bikes) which will ensure caliper is in line with rotor and not letting one edge of pad contact early (causing wear then noise). This is usually found on bikes where the noise will go away for a ride then come back after following the top procedure.

I get asked why these bikes require so much brake maintenance and often get replies saying "I rode moto for years or on the street and never" These are race bikes and require rac bike maintenance. Comes with the territory.

Please let us know what works!
 
1 - 8 of 8 Posts
Top