Brake rotor limits.

[njbray]

My front rotors measure 22.5mm thick - The minimum for front rotors is 22.6mm.
Sooo... I'm wondering if I need to replace them ASAP of if I can wait until after
Rennsport Vl which is next week. We will be driving up and back on Highway 1, hopefully at a spirited pace!
Is a bit risky to put 5 or 600 miles on these? or is there still enough to be OK?
I'm just a bit short on time.

[thstone]

Yes, they will be fine. Just make sure that your pads are in good shape.

(assuming that they are solid rotors, the above is fine. If the rotors are drilled, don't drive them if they have cracks coming from the drilled holes)

[njbray]

The pads and rotors are all genuine Porsche, with about 5mm on pads.
I just don't want this to happen!!!....Especially on Highway 1

[rexcramer]

That brings new meaning to 'slotted and vented.'

Originally Posted by njbray

[steved0x]

I think that the front base rotors are 24mm new, replace at 22mm, and don't machine them.if they are below 22.6mm so i bet you are good and at 22.5mm you still have a quarter of life left and many thousands of miles? Naturally i don't have my book handy...

[steved0x]

Originally Posted by steved0x

I think that the front base rotors are 24mm new, replace at 22mm, and don't machine them.if they are below 22.6mm so i bet you are good and at 22.5mm you still have a quarter of life left and many thousands of miles? Naturally i don't have my book handy...

More info here:
https://wiki.bentleypublishers.com/pages/viewpage.action?pageId=12910663

[njbray]

The 22.6mm seems the correct minimum.
I'm gonna change out the whole lot - just can't do it before next week!

Now it's a question of re-using existing still good pads on new discs or all new pads/discs.

[MWS]

Originally Posted by njbray

Now it's a question of re-using existing still good pads on new discs or all new pads/discs.

Pardon me for saying so, but to me this seems like the obvious "while you're there, might as well" scenario. Any defect on the rotor will mirror itself on the pad, so a pristine rotor should be matched with a pristine pad.

Anytime that I've every tried to save a buck by scrimping, I've always wished I hadn't and ended up with that "why in the hell did I do that?" moment, followed by cursing myself and promising to NEVER do it again...lol. Don't be me.

[steved0x]

Originally Posted by njbray

The 22.6mm seems the correct minimum.
I'm gonna change out the whole lot - just can't do it before next week!

Now it's a question of re-using existing still good pads on new discs or all new pads/discs.

22mm is the wear limit, 22.6mm is only a factor if you need to "turn" the rotor, if you are at 22.5mm you still have 25% left (24mm new, 22m wear limit, which is 1mm per side) which is likely tens of thousands of miles remaining.

If you still have good pads, I would say wait

If you want to do your brakes anyway (it is satisfying to do them all and is is not too difficult), I would say go new all around, new pads to go with your new rotors.

Steve

[Quadcammer]

you got a bunch of wear left. No need to replace them yet.