rotor is <1 year, ~ 12k miles, [~850 track miles]

from centric / zeckhausen so should be good / brembo sized 1 piece


lots of shallow? surface cracks / 'crazing' - more noticable after trackday last sat.

no significant thickness wear, only on both fronts, both rears look normal shiny / smooth

any thoughts? impending rotor detonation or just normal overheated rotor?

Thanks!

and for your entertainment

getting turn 1 wrong (circa 2006, sebring)

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5/9/9 fastest lap 2:44

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Looks normal , and still usable

 

People have told me it's normal. I've been told that once enough of the tiny cracks line up, they'll eventually form a bigger crack, and then the rotor will "crack" in the usual sense. Then it's time to replace it

You could ask Zeckhausen, they have always been very knowledgeable and helpful for me.

 

Looks superficial. Expansion contraction from heat cooling. Keep an eye on them and see if it gets worse.

 

Looks normal. I've seen some guys rub sand paper on their rotors right after a run and swap race pads to street. I haven't done it but supposedly it cleans them up a bit.

Maybe somebody could comment?

 

Thanks, ignoring it for now was my main plan, but, i didn't want bits of rotor falling off...

 

I got this info from Baer several months ago when asking them about this same condition. This was a TSB from GM regarding Corvette rotors.

Bulletin No.: 05-05-23-007

Date: August 03, 2005

INFORMATION

Subject:
Information on Visual Brake Rotor Surface Cracking

Models:
2005-2006 Chevrolet Corvette

with Heavy Duty Brakes (RPO J55)

Important: DO NOT replace OR resurface rotors for small surface cracks that are described below.

The pass criteria for thermal fatigue testing specifies that the rotor is allowed to have small thermal cracking up to 2/3 of the brake plate surface. The brake plate surface for the front rotor is 50 mm (1.96 in) radially which means cracks are permitted up to 33 mm (1.29 in) radially across the rotor brake face in length. This would be the pass criteria for the end of severe testing. To have a large safety margin, a rule of thumb - small thermal cracks are allowable and the rotor does not need to be replaced unless the cracks connect from hole to hole or the crack reaches the OD of the rotor.

 

slight update

went with ignoring the tiny surface cracks

but was hard to ignore this!

did ~44 laps sunday 10/4/9 at sebring from 9-12 - normally get 60-70 laps in full day so was on record pace)

stopped for lunch and found this (was slightly smaller there - took pics today at home)

needless to say i stopped and gingerly drove home!

<a href="http://s334.photobucket.com/albums/m410/alfajimBBK/?action=view&current=cracked1.jpg" target="_blank"><img src="http://i334.photobucket.com/albums/m410/alfajimBBK/cracked1.jpg" border="0" alt="Photobucket"></a>

closeup...

<a href="http://s334.photobucket.com/albums/m410/alfajimBBK/?action=view&current=cracked3.jpg" target="_blank"><img src="http://i334.photobucket.com/albums/m410/alfajimBBK/cracked3.jpg" border="0" alt="Photobucket"></a>

new rotors ordered - have 1 oem front caliper / rotor on at the moment

had a couple of increased pedal movement corners but no noticable judder or noise - i just allways do a close walk around inspection while waiting for the lunch hour to go by... and i will keep doing it to!

 

jeez... thats a major crack.

What rotors did you go with?

 

Products
1 x StopTech SportStop slotted rear rotor 322x22mm, Right $109.00
1 x StopTech SportStop slotted rear rotor 322x22mm, Left $109.00
1 x StopTech SportStop slotted front rotor 324x30mm, Right $119.00
1 x StopTech SportStop slotted front rotor 324x30mm, Left $119.00

from zeckhausen.com

the rears are fine just not sure how slotted in front / plain rears would look - might not change the rears for 3-4 more hpdes

the cracked one was from zeckhausen also- the plain centric rotor - it had ~6-7 hpdes use on it and to be completely honest i had seen a suspicious pre crack when changing the brake pads and ordered the new rotors last friday - didn't really expect this though - the 'pre-crack' was just a heavier surface crack but didn't reach to the edge of the rotor (then!)

my thoughts are that the slotted rotors will keep the temp down enough to (hopefully) avoid this - might finally do some brake duct work also - allways meant to just never got around to it...

 

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Sebring Turn 17 10/4/9
braking from ~125 to 90 at the corner

& not getting it quite right....

I haven't done that since 2006, here at turn 1...
braking from ~110 to 75 at the turn in

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is unrelated to the broken rotor but didn't really need it's own thread...

 

Wow, and you couldn't notice it when driving? Very curious how something like that feels to be driven with. Hehe.

 

I have the same rotors I purchased from a member here and noticed they are doing the surface cracks as well.

 

it wasnt quite that bad at sebring - sometime between the 130 mile drive home / 40 miles next day until went to change pads it fractured completely rim to hub

nope never even a judder - weird - possible that the tire held it together until i loosened the lugs and then it popped the rest of the way, it was out of view until the wheel came off

the same rotors that cracked or the same rotors i just bought? - either way i'll be keeping a bit closer eye on brake rotors from now on.

i plan on keeping current rears for track spares and in ~9 months (1/2 current rotor life) i'll order a new set to have on hand.

anyone know if the 2 piece rotors last longer than 1 piece? would have to last ~ 3 times as long to be "economical" [cause i'm cheap and it's a hobby]

 

wow, I think my stock rotors should last a little bit longer

 

I bought these slightly used off another member but the same ones you got. centric blanks. They showed the surface scratches after one track event. I did another and now they are vibrating pretty good. I am swapping them back out today with my stock ones as I have no track events coming up right now.

 

You killed the brake rotor!