disks under thickness

[axewielder]

Hey guys my front disks are at least 4 mm under min specified thickness, pads have loadsa life left though, just wondering if theres much of a problem with this or just leave it until the pads need doin?
There is the thick lip round the outside where it hasnt worn, this is the only thing i can think of that might be a problem but i can easily grind these off.

[Wayne]

I would change the discs asap, much safer.

[gtigolfthree]

As above your brakes will overheat

[AudiA8Quattro]

If you keep running the discs they could crack or actually start to break up eventually.

[axewielder]

yeha i get the cautious point but i was wondering if there is any 'real' problems that will arrise from under size disks, there is pleanty of metal left, and it breaks fine? they are vented so i doubt they will overheat under just normal use?

[AudiA8Quattro]

The less 'meat' on the disc, the less it can dissipate heat.

[axewielder]

yeh i know but im not ignoring you guys, makes sense i was just thinking there is pleanty of meat left, plus they are vented and i really dont do any hard breaking so i cant really just see them overheating, yes im sure they wouldnt like being taken to the track but many cars have solids and can cope fine with heat dissipation. Just curious as to other things that i may not have thought of?

[AudiA8Quattro]

I don't think you are getting it mate.
You are just thinking of the surface area of the disc, instead think of it as cubic area.
The less cubic area, the more the disc will heat up. Once it is below the manufacturers minimum thickness, the brakes will start to overheat, and that is just for normal road use.
This could lead to brake fade, cracks, or the disc breaking up.
Not that many cars have solid front discs now as they are crap 

[axewielder]

No i get you man probebly wont risk, sorry if i was sounding ignorant+ stuff, appreciate your input 

[Matty-MK3]

Deffo get them done. It's really not safe at all. If they crack, then you have no brakes.