Sceaming brakes

[LaszloB]

My brakes have been screaming since new. Especially the last few feet of a stop, both front and rear (150 miles on the bike). I've cleaned the disc and they are good for about 1 brake, after it goes back to squeaking. I've never owned a bike with disc brakes. I did order a couple extra pads I will be installing this weekend...The pads appear centered, no drag, stops fine with the exception of the squeaking. Anything else I should look at?

The bike is a M2S with Tektro hydraulic disc brake pads

Thanks

 

[CashMoney]

Brake pads need to be "bedded" to the rotor (disc) to deposit brake pad material into all the nooks and crannies on the disc.

The following is from SRAM:

What is the bed-in procedure (brake preparation)?

When pads and rotors are new, they have to be “bed in” before they reach their full braking potential. This is achieved by first accelerating the bike to a moderate speed and then firmly applying t...

sram.zendesk.com

When pads and rotors are new, they have to be “bed in” before they reach their full braking potential. This is achieved by first accelerating the bike to a moderate speed and then firmly applying the brakes until you are at walking speed. Repeat this process 20 times. Then accelerate the bike to a faster speed and apply the brakes until you are at walking speed. Repeat this process ten times. It’s important that during this process you never come to a complete stop or lock up the wheels at any point. The idea behind bedding in a brake is to evenly distribute pad material across the rotor to improve the coefficient of friction between the two components. Coming to a complete stop causes a build up of pad material in one spot that can lead to pulsing and noisy brakes.

 

[rich c]

Who set them up and adjusted them when new? Are the pads centered on the disc? There must be 50 videos on youtube on brake noise, it would easier for you to watch them instead of typing a paragraph.

 

[LaszloB]

Who set them up and adjusted them when new? Are the pads centered on the disc? There must be 50 videos on youtube on brake noise, it would easier for you to watch them instead of typing a paragraph.

Thanks, no one...... It was supposed to be set up to ride

 

[LaszloB]

Brake pads need to be "bedded" to the rotor (disc) to deposit brake pad material into all the nooks and crannies on the disc.

The following is from SRAM:

What is the bed-in procedure (brake preparation)?

When pads and rotors are new, they have to be “bed in” before they reach their full braking potential. This is achieved by first accelerating the bike to a moderate speed and then firmly applying t...

sram.zendesk.com

When pads and rotors are new, they have to be “bed in” before they reach their full braking potential. This is achieved by first accelerating the bike to a moderate speed and then firmly applying the brakes until you are at walking speed. Repeat this process 20 times. Then accelerate the bike to a faster speed and apply the brakes until you are at walking speed. Repeat this process ten times. It’s important that during this process you never come to a complete stop or lock up the wheels at any point. The idea behind bedding in a brake is to evenly distribute pad material across the rotor to improve the coefficient of friction between the two components. Coming to a complete stop causes a build up of pad material in one spot that can lead to pulsing and noisy brakes.

Thanks, I'll swap the pads out and try this

 

[CashMoney]

No need to swap the pads. You can do this with the old pads. If it doesn't work, try it again. If it still doesn't work, then you could swap the pads, scuff the discs with sandpaper, and try with the new pads.

 

[LaszloB]

No need to swap the pads. You can do this with the old pads. If it doesn't work, try it again. If it still doesn't work, then you could swap the pads, scuff the discs with sandpaper, and try with the new pads.

Thanks for your help

 

[fooferdoggie]

Thanks, I'll swap the pads out and try this

get some 120 or so grit sandpaper and sand the rotors and pads to clean them up. be sure to put the pads in the same way so don't swap inside and outside pads. then break them in properly and see how it goes. be sure to clean them with alcohol before riding ot make sure there is no oil on them.

 

[LaszloB]

Thanks for your help

 

[Sierratim]

Thanks for your help

So, how'd it go? Screaming brakes all fixed?

 

[LaszloB]

So, how'd it go? Screaming brakes all fixed?

Thanks, yes they are, actually changed out the pads twice. Ended up with organic pads, the might not last as long but they are very smooth and completely silent

 

[Sierratim]

Thanks, yes they are, actually changed out the pads twice. Ended up with organic pads, the might not last as long but they are very smooth and completely silent

I had the same experience with the OEM pads on my ebike. Very quite with no bedding-in required. Unfortunately, we live in a very hilly area so they only lasted ~500 miles. Glad i checked them or I'd have needed new rotors as well. Depending on where you live you might want to check more often than you might otherwise think necessary.

I tried metallic pads for longer life, but could not get them to quiet down. Switched to 'semi-metallic' pads by Kool Stop. Some bedding-in was required. At 500 miles they were down only ~2% on pad thickness. I think I've found a winner for our hills.

Ride On!...

 

[LaszloB]

I had the same experience with the OEM pads on my ebike. Very quite with no bedding-in required. Unfortunately, we live in a very hilly area so they only lasted ~500 miles. Glad i checked them or I'd have needed new rotors as well. Depending on where you live you might want to check more often than you might otherwise think necessary.

I tried metallic pads for longer life, but could not get them to quiet down. Switched to 'semi-metallic' pads by Kool Stop. Some bedding-in was required. At 500 miles they were down only ~2% on pad thickness. I think I've found a winner for our hills.

Ride On!...

Which Kool Stop pads did you use? The one for Electric Bikes?

 

[indianajo]

On cars we used to sand the rotors in a radial direction during a brake job. Used a belt sander & rotated the rotor. Then they were quiet. My cable pull tektros don't make noise but I'm using organic pads.

 

[Sierratim]

Which Kool Stop pads did you use? The one for Electric Bikes?

My ebike is equipped with Shimano XT BR-M8000 calipers. As far as I know the only Kool Stop pads for these calipers is their KS-D635K.

The aggressive heat sink contributes to pad life as well

Installed with 203mm front rotor and BR-M8000 caliper

 

[LaszloB]

Thanks, they don't have them for mine. Not a big deal, the organics seem to be working fine, I just need to check them more often. The front is simple enough to change by taking the wheel off. The rear however I haven't attempted to take the wheel off. I was not able to change the pads with the wheel or brake attached. Just not enough room to do it. I ended up removing the two bolts from the brake and changing the pads. It took me a little while to properly align the brake with the rotor and re-tighten but it work out

 

[Sierratim]

What bike/brakes do you have?

 

[LaszloB]

M2S Bike, Tektro hydraulic brakes

 

[Sierratim]

Thanks. I wasn't aware you had to pull the wheel to even check the pads on these brakes. Now I see why!

 

[LaszloB]

Thanks. I wasn't aware you had to pull the wheel to even check the pads on these brakes. Now I see why!

Yea, never really thought about it when I got the bike. Maybe their is a way to pull the pads on the rear brake without actually removing the brake from the frame but I have not figured it out and the instructions for the bike are pretty lame