PF brake discs - are they really any good!?

[DuncanR]

Originally Posted by shimmy

Maybe although I dropped off the RS29 at the rear because of the opposite problem.

How can brake bias be changed other than pad types?

Hydraulically ! .. Im not familiar with technically how its done on a road going CSL, but you can change it in car in a race car. There will be a bias valve somewhere in the system which adjusts the braking depending upon how hard your car dives forward ! ... im probably talking bollox now and trying to sound clever, someone more learned with pop up with all the answers in a minute ... cue Gorilla, NZ Tom, Nathan et al !
Does your backside ever feel a bit loose Shim ? suggesting that the car IS more front biased ? BBK's are the thing that has an effect on the brake bias, especially if you only fit them to the fronts and not the rears ... well dont they ?

[_Nathan_]

No adjustable bias valve on a normal CSL - ways of changing the Bias I guess would be piston area, pad area, disk size\distance of caliper from hub & pad compound?

[shimmy]

[quote=_Nathan_;58041]What are you running on the rears now then? If DS2500 over RS29 then you'll be using the front brakes more?

[quote]

well def RS29 last 20% longer, i have a few years proof

but therefore surely if the pad is lasting longer the disc isnt

[_Nathan_]

Not sure I follow that logic?

Look at the friction graphs - that is proof that there is more heat and friction generated at the disk face - that has to have an effect on disk wear?

[shimmy]

Originally Posted by _Nathan_

Not sure I follow that logic?

Look at the friction graphs - that is proof that there is more heat and friction generated at the disk face - that has to have an effect on disk wear?

in my simple mind irrespective of the heat generated by this pad you are stopping the same car from the same speed so energy dissipated is the same so maybe more heat but maybe for shorter period

surely the harder the pad the more wear on the disc for the same exercise!

[_Nathan_]

I'd have thought wear was a function of friction rather than just pad hardness?

Get some temp paint on the new disks, be interested to see what is going on...

[shimmy]

Originally Posted by _Nathan_

I'd have thought wear was a function of friction rather than just pad hardness?

Get some temp paint on the new disks, be interested to see what is going on...

as DS3000 prove, the compound of the pad will have a big effect on disc wear, not always the grippiest wears most. One side is always the weaker and my guess is wioth RS14 the pad wears forst and RS29 the disc more

Friction is what is caused by both touching - which wears more or less depends upon their make up

[_Nathan_]

Have you got the friction curve for DS3000? Very high I suspect? Is there a pad that is low in friction yet still wears disks at a very high rate?

I still think RS29 are kinder to disks :P

[glendog74]

Originally Posted by _Nathan_

I still think RS29 are kinder to disks :P

What he said ^^^

[shimmy]

Originally Posted by _Nathan_

I still think RS29 are kinder to disks :P

you may be right........

but theefore you are saying the RS29 wears slower and the disc wears slower and it stops the car as well or better - something doesnt add up!