Answered Sram guide re brakes

[Welshrobinireland]

Hi all. Tips or solutions please. I had the re brakes on my old overvolt and cant ever remember them being nice and quiet, to a point where after trying all cleaning and sanding, I replaced both the rotor and pads. Still wouldn't shut up. Then on my Scott I had xt rear and saint up front, and apart from the odd squeal were nice and quiet with fantastic stopping. My new bike has the re brakes again and yup, you guessed it screeching. I've got new organic pads on the way but is it me or is this normal for the guide re brakes. I'm even looking at hope replacement. would love shimano but lots of messing with the cable routes.

 

[dirt huffer]

Before you drop a bunch of cash on a new brake system, try out different style rotors. They're all the same thickness so all you need to do is get the same diameter. Heck, you could even try throwing on some Hope rotors.

I still can't believe sanding didn't take care of it though... What grit are you using? Maybe try 80 grit and scratch the hell out them "against the grain" The idea is to break up the harmonic groves worn into the rotor

You can also scuff up your brake pads a bit too. But go easy. Sandpaper will take them down rather quickly.

 

[Gary]

All rotors are not the same thickness

Sorry my REs don't make any noise.
I only use sintered pads (on all my brakes)
have you checked caliper alignment/tightness/vibration

I have Hopes and Shimano on other bikes.
Prefer the guides by miles.

 

[Welshrobinireland]

Only used a very fine

All rotors are not the same thickness

Sorry my REs don't make any noise.
I only use sintered pads (on all my brakes)
have you checked caliper alignment/tightness/vibration

I have Hopes and Shimano on other bikes.
Prefer the guides by miles.

Was the first thing I checked. they were squealing from word go. That was just up and down the driveway to bed them a small bit. Not moving too quickly and short sharp pulls is all. It's a horrible noise

 

[steve_sordy]

The Guide RS I have on my Whyte and the Guide RS I had on the Capra never squealed.

The Shimano BRM 520 on my Focus Jam2 are squealers. I thought they had picked up contamination from when I carried the bike on my tow bar rack. But not so, they just squeal when wet.

If you pedal with the brakes on for a short while and release, the squealing stops. I reckon its when the pads/discs get hot. But once they get wet they squeal again. The pads won't last long at this rate!

Does anyone know whether just changing the pads will fix this?

 

[Gary]

Loads of shimanos do leak fluid from the caliper.
it's a fairly well known issue with the pistons and mainly happens when you leave the bike for a while unridden rather than in use.

I have shimano *2xDeore, Guides *2xRS 1xRE, Avid and Hope brakes.
none squeal other than maybe the odd late braking moment in the wet when the disc is saturated and it stops after a single pad engagement which is perfectly normal.

 

[Topov]

I have used Guide r, Guide RS and Guide RE, only ever squeaked first thing in the wet, but after using them once or twice, absolute silence, I use sintered pads also, even tried cheap ones and still no noise, only noise came when contamintated

 

[Welshrobinireland]

I have used Guide r, Guide RS and Guide RE, only ever squeaked first thing in the wet, but after using them once or twice, absolute silence, I use sintered pads also, even tried cheap ones and still no noise, only noise came when contamintated

I've some cheap organic on the way. Have to be worth a try

 

[ccrdave]

we have a brand new carbon expert levo with code brakes, first we had to change the rotors as the brakes would "pulse" another set of centerlines fixed that but now both brakes have completely failed.
apart from guide re's I hate sram brakes!!

 

[dirt huffer]

Only used a very fine

Yeah, try some more aggressive sand paper and scratch them up and down, not circular with rotation of the rotor, to brake up the harmonic channels cut into the rotor. You want to make sure you're leaving visible scratches on the rotors surface, perpendicular to how the pads rub against the brake surface. It should do the trick...

 

[Welshrobinireland]

Yeah, try some more aggressive sand paper and scratch them up and down, not circular with rotation of the rotor, to brake up the harmonic channels cut into the rotor. You want to make sure you're leaving visible scratches on the rotors surface, perpendicular to how the pads rub against the brake surface. It should do the trick...

So use the sandpaper on both the rotor and pads?

 

[dirt huffer]

So use the sandpaper on both the rotor and pads?

Start by just doing the rotor. Get it good and scratched up. Then take if for a fast ride down the street and see if that takes care of it. Make sure you're using more aggressive sand paper to re-surface the rotor

As a last resort you can try lightly sanding the pads. Lay the sandpaper on a flat surface. With the pad removed, with even hand pressure, drag it across the surface. Just do this 2-3 times max. It will wear the pad down quickly. You'll want to use fine sandpaper for this. I usually only do this when my pads get glazed over and lose their bite.

Really you just want to break up how the pads and rotor have worn. The pads contacting micro groves that have worn into the rotor are what are generating the noise. Sanding breaks this up

 

[R120]

Before doing anyy of that I would check the clamping of the brake cable - quite often brake noise is actually resonance with the frame, caused by the braking forces being transmitted - I had this problem with my Guide RE's on my hardtail, the rear brake was like a fog horn. In the end I changed to a smaller 180mm rotor which solved the problem, as the 200 was just putting too much force down, but before I did that I loosened off the zip ties holding the cable, as they where so tight that when applying the brake, the movement in the calliper resining against the mount was transmitted down the cable into the frame - loosinging off the cable ties made a significant difference.

I have been running RE's on two bike for about 3000 miles now, and apart from the initial issue on the hardtail they have been faultless, and only noisy on the west of days under very hard braking.

They are sensitive to correcting bedding in though, and I think this is the case with bigger rotors generally - if you haven't bedded them in properly then they will make a noise.

 

[Kernow]

Just get out and have a good ride , I bet they stop squealing when they have had some use , expecially after a wet dirty ride , the grit and crap will abraded the discs . Always find organic pads much less likely to squeal and better in the wet and at about £5 a set who cares

 

[Levo]

Hi, I also have the RE on mine, they are very good brakes despite what others say, Yes they squeal but this is normal when they have got wet, I have M4 hope on the other bike and they do the same.

An old trick was to get some dirty puddle water and pour it over your calliper and rotor then ride it, braking the pads and rotors back in this way as you would for new ones, the noise will go away but it can take a fair bit of bedding into get the noise to stop, I think the folk round my way think I am beating the crap out of a baboon or something the racket bedding them in makes, but it dose work....until the next time