Cryogenically treated brake discs for sprint/hillclimb use.

[MartinM]

Has anyone used these for speed events? I can understand the benefits for road/trackday and possibly race use but I'm thinking that as the process effectively makes the disc harder, would they take longer to get up to operating temp?

[sinizter]

Why would it take longer to get to operating temp ?

[thechosenfamily]

sinizter said:

Why would it take longer to get to operating temp ?

More importantly, why would you want it to take longer.

[MartinM]

As a harder pad compound generally takes longer to heat up would the same principle not apply to discs?
For speed events I want the brakes to get up to temp as quickly as possible!

[Dave Brand]

MartinM said:

As a harder pad compound generally takes longer to heat up would the same principle not apply to discs?

Harder pads probably don't take longer to heat up. It's a function of the relationship between coefficient of friction & temperature. Hard pads have lower friction at ambient temperature, so they need to have some heat in them to perform at their best. Softer pads have higher friction at lower temperatures, but are more fade-prone.

[Trev450]

Hi Martin - missing you in the ASWMC sprint championship this year as numbers are down.

My take on this would be that it shouldn't effect the speed in which the disc gets up to temperature, but is likely to prevent overheating and consequent warping and/or cracking of the discs.

[MartinM]

Dave Brand said:

Harder pads probably don't take longer to heat up. It's a function of the relationship between coefficient of friction & temperature. Hard pads have lower friction at ambient temperature, so they need to have some heat in them to perform at their best. Softer pads have higher friction at lower temperatures, but are more fade-prone.

That's basically what I was getting at. So, would you say that a cryogenically treated disc (assuming that cryo treatment effectively hardens it) would behave in the same way as the hypothetical harder pad, i.e requiring more heat in it than a boggo one for it to perform at it's best?

To pose my original question simply: "Are these cryogenically treated discs any good for sprints hillclimbs (where often you have to get a time with stone cold brakes)? Are they better or worse than OE or aftermarket discs?

[Batfink]

I cannot see you noticing anything different over standard discs other than the amount you spend.

[Dave Brand]

MartinM said:

That's basically what I was getting at. So, would you say that a cryogenically treated disc (assuming that cryo treatment effectively hardens it) would behave in the same way as the hypothetical harder pad, i.e requiring more heat in it than a boggo one for it to perform at it's best?

In pad terms "hard" or "soft" doesn't refer to the actual hardness of the material, but to the way it feels to the driver - in fact a "soft" pad may be physically harder than a "hard" pad.

Without any real information on the metallurgy of cryogenically treated pads it's difficult to say what their effect on brake performance would be. The claims that cryogenic treatment makes the surface more wear-resistant implies that the structure of the metal is changed; that may or may not have an effect on coefficient of friction.

[PhillipM]

Batfink said:

I cannot see you noticing anything different over standard discs other than the amount you spend.

This.