AP Racing disc cracked

[DuncanR]

Lent one of my rears to a mate after he got a puncture at Bedford trackday, (would do the same if any of you chaps are at Bedford and get in trouble, I only live down the road , also if you need a trailer ride home:bigcry: hopefully not, give me a call mob 07768 633717) got it back this morning and upon removing wheel to swap over, noticed a crack on the inner plate of the disc. This had manifested itself in the form of a rotational clicking noise, caused by a rough area of the outer disc plate (see pic)
temporarily picking up the pad as the wheel turned, banging it against the top of the caliper housing and dropping it again. As you can see from the Vernier reading this disc has only got approx. 1 mm of wear on it from its original thickness of 20mm.
The disc I believe is a CP4475-122G8 as the brake kit is a CP5144-1004.G8. There is no evidence of any thermal cracking on the surface of the disc. I know its difficult to estimate how long discs will last as a result of how many track/ring days it has done, but would anyone hazard a guess? Me thinks a visit to Thorney is on the horizon !

[Thorney]

Yeah I think they've had it mate.

[DuncanR]

I was just doing you an email John ! Need I bother? when would be convenient to pop down as we discussed previously ?

[glendog74]

Duncan, could you post up a bigger photo please - i can't quite make out the crack... :clown:

Oops, i just said 'crack' :whistle:

[TANKSLAPPER]

Duncan, I have a 24" screen and your photo are to big for it.

stop large............ing it up

I blame that Adam Forster he's to heavy on the brakes.

:thumbs:

[TANKSLAPPER]

I would use BMW OEM ones on the back they are mile better than AP's

[Thorney]

I was just doing you an email John ! Need I bother? when would be convenient to pop down as we discussed previously ?

Yeah makes sense tbh, when are you around, could have a look later this week or next.

[DuncanR]

There stop moaning ! I do large ! I was in a rush :birdman:

[mattCSnoL]

thanks alot dunc for the loan of the wheel

you may not have noticed the cracks if i hadnt nicked your wheel for two weeks:thumbs:

[shimmy]

That's a strange crack D

like you say no signs of heat cracks and looks like a stress fracture or fault.

If I were you I would get them off and new ones on but send it off to Pete Collins at AP and see what he says.

[_Nathan_]

Stick BMW ones on, they are semi floating, last for ages and are only £75 each or something silly.

[AlexGTT]

Stick BMW ones on, they are semi floating, last for ages and are only £75 each or something silly.

What Nathan said. :thumbs:

[Jaw_F430]

I blame that Adam Forster he's to heavy on the brakes.

:thumbs:



Was one of you guys the one who was sick when Adam was driving on track?


:thumbs:

[mattCSnoL]

that wast me

think it was duncans son:hahaha:

[bromers]

Where/when did you get the disks from ?

I had a set of fronts that didn't last 6 months !! But last ones have been fine. My suspicous mind thinks either dodgy batch or fakes.

[DuncanR]

You are of course welcome Matt, what are you saying then? that you saved my life ?:smt055... fate works in funny ways sometimes, If i hadnt of shagged my best friends wife once .. he would never had discovered that she had the clap !! :hahaha:
I dont think any of us were sick with Adam driving up at Bedford , do you know him then Jaw_F430 ?
Bromers, I have the original boxes for the discs, all AP , and it would appear that they were purchased from Thorney so they will definitely be the real deal ! Im seeing him tomorrow and sending the disc back to AP sounds like a plan as It does seem unusual when you look at the actual disc. I take everyones point about refitting OEM parts .... except Tankslappers cos he is just plain tight !;), my only concern would be the balance of the car under braking with PF on front and just OEM on the back, dont forget im a newbie !! I know both you T$ and Nath are running that setup...oh dear decisions decisions !

[Jaw_F430]

He used to have a Cooper S works GP and thats how I know him from the Mini forum, but I took the CSL to Bedford when there was a few of the mini guys going and ended up letting him show me how the CSL goes:thumbs:



http://www.cslregister.com/forum/showthread.php?t=1807

[DuncanR]

Thats the boy ! He is my daughters, boyfriends sister ...uh ..sorry ..cousin ! I booked him for the day at Bedford as he knows the track so well, and it was well worth it, straight on it, trouble was once I let him drive I couldnt get it back !:bigcry:

[_Nathan_]

Changing the disk won't make any difference to the balance of the brakes, that is a function of piston area, pad swept area and pad compound (obviously disk friction will play a tiny, tiny part in that but nothing of note as the BMW disks aren't rubbish).

I've seen several pics of AP disks like that but none of an OEM disk...

[DuncanR]

Mmmm , good point well made Nathan... I do still have the old disks I just need to check if they be front or rears !...
Calls for "CSL parts are me Craig" :smt024 !

[glendog74]

dont forget im a newbie !!

Not anymore! :banghead:

[Jaw_F430]

Thats the boy ! He is my daughters, boyfriends sister ...uh ..sorry ..cousin ! I booked him for the day at Bedford as he knows the track so well, and it was well worth it, straight on it, trouble was once I let him drive I couldnt get it back !:bigcry:


Yes he did like driving/drifting my CSL:hahaha:

[DuncanR]

Ok Ok Rob...no more :banghead:... done about 3k in the car as of today since Oct 1st ..so maybe not such a newbie !:thumbs:

[glendog74]

;) :whistle: