Noisy rear brake

[Tmeyer37]

So I have put just over 200 miles on my 2020 Trance e+1 and since day one the rear brake is really loud. Its almost like a screech i thought it was dust in my system causing a vibration then noise but cleaning the rear caliper didn't really do anything. The brakes perform well but its just annoying, anyone else experiencing this? This are Shimano XT 4 piston brakes.

 

[Trancer]

Try a thin smear of HT grease (Copaslip etc) on the BACK of the pads.

 

[urastus]

loose mounting bolts? Did you bed the pads in when new? Apparently glazed pads will squeal. You could try lightly sanding the pads (get rid of glaze), then bed them in. This dude uses a proprietary spray that essentially does the same thing. I'm guessing the brakes he fixed were glazed. This is probably a better video - it also addresses the contamination theory posed by jamze below. You inspired me to look; one of my old bikes has a squawking rear which I've been putting up with.

 

[Jamze]

Could be contaminated pads too. Swap the front/rear pads, see if the screech moves with the pads?

 

[steve_sordy]

Contaminated pads. Could be picked up from the road when riding the bike or transporting on the car. Or it could be you after enthusiastic lubing of chain or mech.

Discard pads, clean disc, fit new pads, bed in.

Or do the "Disco Inferno"!

 

[DrStupid]

Mine was loose mounting bolts. They were finger tight when it started making noise.

 

[TheBikePilot]

Try loosening your mounting bolts. Squeeze the brakes and tighten up the mounting bolts with the brake still applied.

Failing that sounds like contaminated pads. Won't harm to clean the discs either. Us Propylene Alcohol or get Disc Cleaner (It's just PA). A new set of pads is around £15-20, very easy to change.

 

[Tmeyer37]

So I did a full cleaning of the bike yesterday and I recentered the brake caliper. Went for a 20 mile ride and it was completely silent, I tested hard braking and long sustained braking down a long hill. On the last mile or so on one of the down hills it made some small noise from the rear again but seemed to go away quickly, maybe dust build up? The last 2 miles or so of my loop is pretty flat but dusty gravel and no brake usage so maybe that was dust build up.

 

[urastus]

So I did a full cleaning of the bike yesterday and I recentered the brake caliper. Went for a 20 mile ride and it was completely silent, I tested hard braking and long sustained braking down a long hill. On the last mile or so on one of the down hills it made some small noise from the rear again but seemed to go away quickly, maybe dust build up? The last 2 miles or so of my loop is pretty flat but dusty gravel and no brake usage so maybe that was dust build up.

Awesome! Re the long hill - I have a couple of long (1km) steep descents full of ledges and washouts - lots of hard braking. When I get close to the bottom, rear brake starts to squawk - I use the rear more because there is usually something the front has to get over. I'm pretty sure it's heat related, and I've got resin pads if that means anything. Once I reach the bottom, it's undulating and no more noisy brake.

 

[Tmeyer37]

Went for a pretty hilly ride today and the noise returned but was intermittent. When I got home I pulled the pads and found they were pitted pretty bad, i took some fine grit sand paper to them to smooth out the pits then went over it with some emerypad to scuff the pads up a bit. Rode around the parking lot and the sound is gone again. Gonna get some new pads though, any idea why relatively new pads (250 miles) would be pitted already?

 

[urastus]

Went for a pretty hilly ride today and the noise returned but was intermittent. When I got home I pulled the pads and found they were pitted pretty bad, i took some fine grit sand paper to them to smooth out the pits then went over it with some emerypad to scuff the pads up a bit. Rode around the parking lot and the sound is gone again. Gonna get some new pads though, any idea why relatively new pads (250 miles) would be pitted already?

Are they resin? Mine came with brakes not suited to my area I could avoid the big descents, but I think I'll get sintered pads next - the rear rotor I replaced is metal pad compatible. Front can stay resin - rotor is resin compatible only.

 

[Tmeyer37]

Are they resin? Mine came with brakes not suited to my area I could avoid the big descents, but I think I'll get sintered pads next - the rear rotor I replaced is metal pad compatible. Front can stay resin - rotor is resin compatible only.

I am not sure, I havent looked up the pads yet.

 

[Tmeyer37]

Are they resin? Mine came with brakes not suited to my area I could avoid the big descents, but I think I'll get sintered pads next - the rear rotor I replaced is metal pad compatible. Front can stay resin - rotor is resin compatible only.

They arent resin, just the standard stock pads. Noise was coming back. I went to my LBS and they had a set of pads for just about every single caliper ever made except for the XT 4 piston..... so I pulled the pads again when cleaning my bike today and hit them with sand paper again, then alcohol and made them nice and shiny like they were new, I also ran the sand paper over the rotor as well and bedded them in again with some tricks I learned on GMBN videos and then my front started making noise so I gave the front the same treatment. Went on a 23 mile ride and both were silent and felt stronger. I was using wet chain lube because that is what I had, I picked up some dry lube while I was at the shop so I switched over to that. I think I got over zealous with chain lube before and contaminated the pads but seems as now problem is solved. I love the power of these 4 piston brakes.

 

[TheDudeAbides]

They arent resin, just the standard stock pads. Noise was coming back. I went to my LBS and they had a set of pads for just about every single caliper ever made except for the XT 4 piston..... I think I got over zealous with chain lube before and contaminated the pads but seems as now problem is solved. I love the power of these 4 piston brakes.

I'm curious, did the problem ever come back or was the issue truly resolved?

I have the same bike as you, reading all of your posts felt as if I was reading my exact problem ... except that my problem will not go away. Over the past 6 mos, I've realigned the calipers at least 8x; sanded pads 5-6x; cleaned rotors 5-6x; replaced both sets of pads; replaced both rotors. Each of these steps worked for a period of time (sometimes a single ride, sometimes a few rides, sometimes a couple of weeks) but then the problem resurfaces. Has been looked at by two diff LBS - one of which cleaned the caliper pistons thinking maybe one or more were getting stuck ... didn't help.

FYI - I use dry lube on my chain and apply after riding so lube can't be the issue.

 

[Krrr]

Me too! I got the same problem. Come on, solve it. The noise scares the turkeys.
Only thing, other than the long handlebars, and chain stretch on the top gear.
I love my TranceE+1 PRO.
Winter here now in PA.
Does anyone have a way to drain the battery down, while in storage?
Thanks everyone. Be well.

 

[TheDudeAbides]

Krrr - Front, back or both wheels? I get serious vibration on the front at certain speeds and lever pressures.

 

[Krrr]

Krrr - Front, back or both wheels? I get serious vibration on the front at certain speeds and lever pressures.

The rear brake, but only for a while, then ends, then returns. Maybe a third of the ride.
I thought it could be oil. Great Bike. Can't imagine what those super $$$$ EBikes do!!
I call my ETrance a Peloton in the woods.

 

[TheDudeAbides]

UPDATE: SOLVED (for me at least) -- I finally solved the problem by swapping out the Shimano rotors with Magura MDR-P rotors and I also switched to MTX ceramic pads. The Magura's are 2.0mm thick vs the Shimano's at 1.8mm. Doesn't seem like a lot but after 1 month of fairly heavy riding I've had zero noise and zero vibration.

Not sure if it was the rotors, the pads, or the combo that did the trick but I am so relieved. Might be worth a shot for others.