RacingBrake Header H1 Image
General Information
    About Us
    Brake Technology
    Feature Comparison
    Product Knowledge
    Search by Category
    Find a Dealer
    Become a Dealer
    Dealer Login
Media Center
    General Discussion
    New Development
    Product Reviews
    Key Messages Posted
    Latest Topics
    Contact Us
    Privacy Policy
    Tech Tips
    Warranty Information




Go Back   RacingBrake Forums > Category > New Development

Thread Tools Search this Thread Display Modes
Old 03-13-2017, 05:04 PM   #1
racingbrake's Avatar
Default Sintered brake pad for CCM rotors

After using OE pads with heat cycles - Surface pitting shown.

Two track events after using RB sintered pads.

racingbrake is offline   Reply With Quote
Old 03-14-2017, 08:31 AM   #2
racingbrake's Avatar

Sintered process is not a new technology but only some are used as brake pad for motorcycles, very few in car application, and none exists in high performance/CCM brakes.

Sometime it s/b easier for general readers to call it as a "Full" metallic brake pad vs."Semi-metallic" pad that is commonly known and widely used.

Making sintered pad is far more difficult and taking much longer time to make than traditional semi-metallic, as it's 100% metallic powder with more than a dozen of ingredients that's molded together via high heat and pressure, no resin nor additive like semi-metallic which certain metallic ingredient are bonded together by resin and the resin (of plastic nature) can only resist to certain temperature, when over the threshold temperature, the resin will melt and the metallic powder can no longer be bonded together so the pad will accelerate its wear, and emit the resin (commonly known as deposit) to the disc surface which can cause all kind of brake issue - vibration, loss of braking power etc.
racingbrake is offline   Reply With Quote
Old 04-11-2017, 04:00 PM   #3
racingbrake's Avatar

Before and after sintered brake pad transfer on worn out carbon ceramic rotor.

racingbrake is offline   Reply With Quote
Old 05-14-2017, 08:19 AM   #4
racingbrake's Avatar
Default How to restore your damaged CCM rotors at no cost

The friction couple (pad and rotor) compatibility is very important in the performance of all brake systems, not only carbon ceramic. However since CCM rotors generate much more heat than conventional iron (due to its lighter weight), so it's even more crucial in carbon ceramic application.

To achieve a healthy braking operation it's necessary to transfer a layer from the pad surface on to the rotor face. For iron rotors (with semi-metallic pads) this usually can be achieved with careful selection of iron rotor material and brake pad compound.

However since the CCM rotors brake is running at a higher (~30%) temperature level than iron so using conventional semi-metallic pad becomes challenging due to the temperature limit of resin that holds the friction ingredient together. Resin is of plastic nature so when the pad is heated up it becomes soft and starts losing its binding strength, that's when you feel brake fade and notice resin emitted to rotor surface with uneven/un-uniform layers (bad deposit) that will cause vibration and other ill effect.

Sintered pad on the other hand, uses no resin, and is of full (100%) metallic, it's composed of various metallic powder. Those powder were compressed together under extremely high pressure, under very high temperature, takes days to cure and form together with the steel backing plate which is made of high tensile strength alloy steel so they for more resistant to deformation (warping) under repeated heat cycles.

During bed-in process the sintered pad starts transferring a very "uniform" layers (good deposit) over to rotor surface which also forming a protective coat on rotor surface, from thereon the friction is taken place between the transferred layers between the pad and rotor surface.

If a CCM rotor is already damaged (pitted-rough surface) due to the heat stress & incompatible pads, after bedding in with sintered pad, those surface will begin to heal, and eventually the metallic layer will smooth out the entire disc surface, we used dial gauge to check run out on those healed surface and the run out is within the tolerance of .00013"

During this rotor surface healing (patching) process you will notice the pad will wear out faster than normal, but after the rotor surface is restored not only the rotor life is to be prolonged, but the pad wear rate will become normal.
racingbrake is offline   Reply With Quote
Old 05-14-2017, 08:49 AM   #5
racingbrake's Avatar
Default Difference of friction methos between Iron and CCM

The method of friction between ceramic discs and pads work differently than iron discs.

With iron discs it is the friction between the disc surface and the pad surface that provides the braking force, but with ceramic discs it is the friction between the pad material that has been laid onto the disc surface and the pad itself that is what provides the braking force.

After properly break in, what you would expect to see on the surface of the rotor is a nice uniform, reflective layer, which signifies the transfer of material from the pad onto the rotor*. If the transfer layer is patchy or streaky then this would indicate that the pad is operating out of its temperature window. Pitting on the surface is the initial signs of disc wear, where the carbon in the disc is oxidizing.

CCM rotor surface is as hard as a diamond, so no brake pad can ever wear the rotor down. The only possible cause that can damage the rotor is from over-heat that causes carbon to oxide and lose its weight, rotor surface becomes pitted which will wear the brake pad down like a sharp grinder. This is the point when the rotor require replacement or re-furbishsing.

OE requires rotor weight check with instrument and complicated process, so to help user better understand we have published an article - "How to determine when to replace CCM rotor ring"

However we suggest "rotor surface check" is an easy and more practical way to check the healthiness of CCM rotors - If your brakes performs well, rotor surface looks good, and brake pad wear is normal then you should not be worrying about the weight.

*Transfer of layer from the brake pad to CCM rotor is a fusion process which can only take place with a right sintered compound under a high temperature that only CCM rotors can generate (not iron rotors)
racingbrake is offline   Reply With Quote
Old 05-14-2017, 08:54 AM   #6
racingbrake's Avatar

Some conversations re weight checking:

Originally Posted by CAOZKAN View Post
I wanted to update you about my situation. Even after my markers were almost completely gone and we assumed that the rotors needed to change, I went on a trip for 6000km. During this trip I was very stressed about the rotors and everytime I pressed the brakes there was a weird sound and vibrations.
I wrote and complain about rotors to BMW HQ, and Turkey dealer called me and they took the car for inspection. After one week, today I received a call from them, they are saying that they weighed all the rotors and they all had an average around 7.4kg vs min. 7.1kg ; therefore they concluded that there was no necessity for the rotors to be changed.
One side of me is really happy about the fact that even after the markers are gone, there is plenty of rotors left. On the other hand, if this is the case, how in future I will be able to understand the conditions of the rotors and why this sound and vibrations were happening. I really appreciate any comments/guesses about this issue.
Originally Posted by racingbrake View Post
Here is RB's comprehensive write up on CCM rotor replacement:

Note all presentation are based on published and imprinted numbers w/o subject opinion.

Nonetheless my recommendation to those who run CCM brakes is to use "visual" inspection to the rotor (surface) conditions than those "weight" or "wearing mark" suggestion, because all the braking debris build up in the drill holes do add up to the rotor weight* which can give false signal.

The weight or wearing mark suggested by the CCB rotor mfgr are something quantitative for a consumer to reference and observe, how you "feel" is still more important. I have seen people replace their CCM rotors due to ill operation, but hardly seen anyone replaces their rotors due to below minimum weight.

*Unless you clean up all the holes (clean with a pin and compressed air) after track days which I know only very few track racers doing this to keep their CCM rotor in shape. If you don't this regularly, over the time those accumulated debris becomes as hard as iron bits and block the holes, and can no longer be removed.
racingbrake is offline   Reply With Quote
Old 05-19-2017, 09:13 AM   #7
racingbrake's Avatar
Default Russ' RB CCM Kit set up

OE set up

OE caliper after running RB sintered pad

RB caliper and sintered pad installed

Front set up

Rear set up

Real Brake for the Real People.
racingbrake is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is On
Forum Jump

All times are GMT -7. The time now is 04:52 AM.
View Forum Archive.
Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
  TPM Products Inc. Copyright 1985 - 2009 TPM Products, Inc. TPM® and RacingBrake are our trademarks.
1556 Kimberly Avenue, Fullerton, CA 92831, Phone: 714-871-6392 Fax: 714-871-9736