Z4M: Cobalt Friction Brake Pads (possible Group Buy)

Cobalt now has a listing - D946 fronts - as The Hack pointed out; size is almost identical to the D394 on the non comp e46 M3. I'm not looking for a track only pad and I only drive the car in warmer months. My connection at Federal Mogul on the Ferodo DS 2500's has not come through? Price may swing me over to the new StopTech Street Performance pads. I have the winter to decide.

Originally Posted by pal

(1) They work via chemical friction i.e., by transferring a layer onto the pad and working against that. Hence, they are very rotor friendly. Unlike most pads out there that use mechnical friction which digs into the rotor for stopping.

(2) No bedding in needed since they dont use resins for bonding.

1: What pads work by abrasive friction (pretty sure that's what he meant by mechanical) I don't think there are any, they all operate on adherent friction (what he refers to as checmial I guess)

2: Bedding is that initial even transfer of the pad to the rotor that he apparently mentioned...

I think there was a misunderstanding.

Originally Posted by blau335

1: What pads work by abrasive friction (pretty sure that's what he meant by mechanical) I don't think there are any, they all operate on adherent friction (what he refers to as checmial I guess)

-Actually pads work by both abrasive and adherent friction, at different points depending on the temperature range that they are designed for at what they are experiencing at any given moment.

Originally Posted by Palantirion

-Actually pads work by both abrasive and adherent friction, at different points depending on the temperature range that they are designed for at what they are experiencing at any given moment.

You know what I meant, they aren't meant to stop using abrasive friction, all it's there for is to add heat to get into their operating range.

That's like saying your motor is run by the starter, sure it's run by it for a few seconds, but it's meant to run on gas.

Originally Posted by blau335

You know what I meant, they aren't meant to stop using abrasive friction, all it's there for is to add heat to get into their operating range.

That's like saying your motor is run by the starter, sure it's run by it for a few seconds, but it's meant to run on gas.

-Actually at 12 to 14:1 I'd say the engine runs on air, gas is just the catalyst

Brakes used outside of their operating range still function fairly well (IE: HT-14s at street temps, or street pads at track temps), but have negative side effects and don't reach optimum performance. Unlike a car engine being driven by a starter motor, which does not come close to achieving the typical performance of the engine. Try again with your metaphor...

I called Cobalt again today to clarify and got a better (or more complete) answer. They say you dont need to "bed" in the XR pads when using them with a new rotor or a rotor that was using XRs before. These pads are high carbon and the technology they use (resins etc) allow for pads to be used right out of the box.

Now if the XRs are used with a rotor that had another pads' transfer layer on it, then you need to do some bedding to remove the other transfer layer and put this one on. For this they recommend about 3-4 laps and then about a 15-30 minute cool down time. After that, you should be good to go.

Anyone try Cool Carbon yet? The Hack has them on the rear - looks like a good all purpose pad...

Originally Posted by Palantirion

-Actually at 12 to 14:1 I'd say the engine runs on air, gas is just the catalyst

Brakes used outside of their operating range still function fairly well (IE: HT-14s at street temps, or street pads at track temps), but have negative side effects and don't reach optimum performance. Unlike a car engine being driven by a starter motor, which does not come close to achieving the typical performance of the engine. Try again with your metaphor...

You're moving away from the point, which is that all pads are designed (does that help) to operate off adherent friction. They are not meant to be used abrasively.

I just think it's funny that any brake company would suggest that the other brake companies would use abrasive friction to stop.