Brake pad advice needed

markyhud

I bought some semi-metallic pads from discobrakes and I've noticed over the past few weeks that whenever I'm on the brakes for any time on downhill sections and the heat builds up they start to squeal. Was just going to live with it but i've been out today in the rain and mud for the first time since getting the new pads. Every time I braked they squealed like pigs on honeymoon. Embarassingly so :oops: !!! It was like an early warning device. Calipers aligned properly, rotors spotlessly clean and no contamination anywhere........so my question is? Why are they so noisy and what are my alternatives? The rotor states "resin pads only". Which pads are classed as resin? Could I try sintered or kevlar with any better results?
I'm running the stock brakes on my Trek 6500 which are Shimano BR M575 (looking to upgrade soon but that thread is for another day)

Matthew J.G.Price

markyhud wrote:

The rotor states "resin pads only". Which pads are classed as resin?

In a nut shell, there are Organic (Resin), Metallic (Sintered) and mixed versions.
You have chosen a mixed version.
Shimano wants you to stick to Resin.

Matthew

.blitz

Many brakes squeal in the wet but I've got some 575s meself and they definitely work best with Shimano's pads, even if they don't last very long. Have tried them with Superstar sintered and they were awful (noisy and wooden) and Superstar kevlar (quieter but still wooden)

Back with Shimano resin pads now and they are most excellent.

sloppycowpat

at least you dont need a bell :P

as above tho the shimano ones are quieter but more expensive,

have you cleaned the rotor with ispropyl alcohol that can sometimes remove o small amount of staff and improve the sound of pigs in a blender

markyhud

The reason i bought new pads in the first place was because I contaminated them with mineral oil whilst bleeding them. To be honest I contaminated half the kitchen too. It was like watching dancing on ice :? So when the new ones arrived I blitzed the rotors with IPA so they are immaculate. I thought I had mentioned in the thread that the front ones (original shimano) were also noisy today. It did my head in!!!!! I don't really want to spend a whole lot on new pads as I think I might change them sometime soon. I had Hayes 9s on my rockhopper before I bought this bike and I loved them. I know a lot of people say they are either on or off but I found them excellent. Even after a damn good bleed these Shimanos are still a bit spongy unless i'm just not used to a hydraulic brake with any real modulation.

cooldad

Brakes can be noisy when they get dry, or in the wet, or in sandy conditions, or in muddy conditions. Especially sintered.
Just live with it.
Shimano rotors say for resin only, but it actually makes no difference. All rotors, whatever make, are made of stainless steel.

markyhud

Just been looking at discobrakes website and think I'm going to try the ceramic pro pads :

"These soft organic ceramic fiber disc brake pads are carbonized. The ceramic compound insulates the brake system from friction heat up to 400oC. The result is a very powerful, quiet pad with extremely low heat generation which all but eliminates the chances of brake fade."
Also "Low Noise: The black ceramic compound C is thought to be virtually silent"


Sounds just the job that

Chunkers1980

It does, but how true that is?

Most things have trade-offs in this world.

markyhud

Chunkers1980 wrote:

It does, but how true that is?

Most things have trade-offs in this world.

Worth a try for a tenner though.

Russ-Tyson

Superstar Kevlar work well and don't squeal and they seem to last well on my Saint 810's

cycleclinic

I use EBC pads mostly and they seem fine. If squeel is annoying you then brake less unless you are heading towards a cliff. Sintered pads don't result in squeel for me but I don't overheat them.

sloppycowpat

I use kevlar superstar pads at the moment had no probs with them they are great and i am also a fan of hayes 9s

cooldad

I normally use SS sintered, but tried a set of Kevlar today and very impressed so far. We'll see how long they last.

Chunkers1980

Front, back or both? I use sintered too and was only thinking today I may try a set of kevlars.

cooldad

Both, killed my last set of sintered on a rather damp Cwncarn last week. Being red, the Kevlars made me superfast today.
Youngster uses the kevlar so got the four pair deal.
Superstar were excellent as usual. Ordered late Wednesday afternoon, arrived in Friday post.
Extra good as I ordered from Cwncarn, but could only get G on my phone, took forever, and once I finished realised I'd used my default address - my office and I'm on leave. Gave them a call, answered on the second ring, and they sent them to my house.

The Rookie

cooldad wrote:

All rotors, whatever make, are made of stainless steel.

Nope, stainless is a rubbish as a disc, they are a steel alloy, but not stainless.

The disc can have an effect, my Alligator disc squealed like a Banshee on even the lightest applications, now I've swopped to an almost as light Tektro (82g now 101g) and it's silent, everything else is the same! The squeal is caused by something hitting it's resonant frequancy, so weights and siffness of calliper, mount, frame, disc and hub all play a part, metal pads are often worse as they have less internal hysterisis and therefor less damping action.

cooldad

The Beginner wrote:

cooldad wrote:

All rotors, whatever make, are made of stainless steel.

Nope, stainless is a rubbish as a disc, they are a steel alloy, but not stainless.

Let's try again - most rotors are made of stainless steel. Some are made of aluminium or titanium (which need special pads), or mild steel =- cheap nasty brakes.
But I would wager that 99% of rotors on forum members bikes are stainless steel.

The Rookie

I'd wager they are not, because as I said, Stainless is a rubbish friction material and mild steel is destroyed too quickly for even Promax to use, so they are a corrodeable steel alloy (mostly) but NOT stainless.

cooldad

The Beginner wrote:

I'd wager they are not, because as I said, Stainless is a rubbish friction material and mild steel is destroyed too quickly for even Promax to use, so they are a corrodeable steel alloy (mostly) but NOT stainless.

OK, google a few manufacturers and see what they use.
But just as a start from Superstar
"Superstar disc rotors are made in the same factory which makes most of the big boys rotors. Made from stainless steel which is hardened then ground flat, for a long lasting rotor with perfect trueness."

bennett_346

Definately stainless steel.

ricardo_smooth

I'm just surprised cooldad got SS to answer the phone :shock: usually doesn't happen! They are good with email however.

cooldad

ricardo_smooth wrote:

I'm just surprised cooldad got SS to answer the phone :shock: usually doesn't happen! They are good with email however.

They know I'm a grumpy bastard.

Gibbo GTI

cooldad wrote:

I normally use SS sintered, but tried a set of Kevlar today and very impressed so far. We'll see how long they last.

How are you getting on with the kevlar pads? Are they lasting well?

cooldad

No wear yet, but I wouldn't expect any.

Gibbo GTI

Cheers, just ordered 4 sets so should do me a long time lol