AP Racing disc cracked

DuncanR · 08-12-2009, 04:09 PM

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

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 · 08-12-2009, 04:13 PM

Yeah I think they've had it mate.

DuncanR · 08-12-2009, 04:16 PM

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

**glendog74** · 08-12-2009, 04:25 PM

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

Oops, i just said 'crack'

TANKSLAPPER · 08-12-2009, 04:31 PM

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.

TANKSLAPPER · 08-12-2009, 04:34 PM

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

Thorney · 08-12-2009, 04:39 PM

Quote:

Originally Posted by DuncanR

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 · 08-12-2009, 04:39 PM

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

mattCSnoL · 08-12-2009, 05:32 PM

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

**shimmy** · 08-12-2009, 05:37 PM

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.

08-12-2009, 04:13 PM	#2
Thorney S5 - Full Throttle Join Date: Sep 2007 Posts: 469 Casino cash: $3876	Yeah I think they've had it mate. __________________ http://www.thorneymotorsport.co.uk

08-12-2009, 04:25 PM	#4
glendog74 CSL Register Uber-poster! Tetris Champion! Join Date: Apr 2008 Location: Cornwall Posts: 8,861 Casino cash: $32299	Duncan, could you post up a bigger photo please - i can't quite make out the crack... Oops, i just said 'crack' __________________ Cha'mone Mother F**ker!

08-12-2009, 04:16 PM	#3
DuncanR CSL Register Uber-poster! Join Date: Sep 2009 Location: Olney, Bucks Posts: 3,735 Casino cash: $9984	I was just doing you an email John ! Need I bother? when would be convenient to pop down as we discussed previously ?

08-12-2009, 04:31 PM	#5
TANKSLAPPER S5, Sport Off, DSC M-track Join Date: Nov 2008 Posts: 801 Casino cash: $8979	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.

08-12-2009, 04:34 PM	#6
TANKSLAPPER S5, Sport Off, DSC M-track Join Date: Nov 2008 Posts: 801 Casino cash: $8979	I would use BMW OEM ones on the back they are mile better than AP's

08-12-2009, 04:39 PM	#8
DuncanR CSL Register Uber-poster! Join Date: Sep 2009 Location: Olney, Bucks Posts: 3,735 Casino cash: $9984	There stop moaning ! I do large ! I was in a rush

08-12-2009, 05:32 PM	#9
mattCSnoL S2 - Picking it up Join Date: Dec 2009 Location: manchester Posts: 50 Casino cash: $107	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

08-12-2009, 05:37 PM	#10
shimmy CSL Register Uber-poster! Join Date: Apr 2008 Location: Uk Posts: 14,646 Casino cash: $43909	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.