Turn down a 12mm disc to 10mm

[orsum]

Now I am confused.

The hat height is measured the front face were the wheel mounts to the back face of the disc.

Why would I need to take 2mm of each face.

Brake Disc
A = Diameter (mm): 302
B = Thickness (mm): 12
Min (mm): 10
C = HT (mm): 42
E = B (mm): 68
D = N: 5
Type: Solid
OE Ref: 4F0615601G

[Error404]

Sorry my mistake, I had a vented disc in my mind. Ignore me

[M_GORDON]

For 1 or 2mm...
down the pads and go go go goooo!!!

[martinjs]

Sorry my mistake, I had a vented disc in my mind. Ignore me

So did I in my first post earlier

[martinjs]

If your making brackets anyway, just adjust the design slightly.

[twoqu]

Tend to agree with LHD. Surely its better to have an off the shelf, readily available unmodified disc then modify it.
Guess you have seen the Epytec brackets for this particular conversion. Below is the translation of the carrier modification necessary.
With our adapters the original Audi S2 Coupé brake calipers of the rear axle can be maintained. The caliper saddle carriers have to be machined at the inner dimensions where the disc runs with a file (0,5-0,7mm)!
So its not a massive amount and I doubt whether its going to be an issue. Appreciate that brakes are safety critical!

[twoqu]

Looking at a typical cross section it is evident that the disc does not have a uniform thickness. You can see that there is actually less material where the bell meets the friction surface in effect. Without having a disc at hand its difficult to estimate its depth. So removing material from the back only will reduce this further. Clearly 1mm is acceptable but perhaps more might be pushing it. The point is who knows for sure whether its going to be an issue.

[orsum]

Good point on the remaining material at the point.

I will check this before doing anything.

Possible 1mm of the disc and the rest off the carrier is the safer route to go.

[twoqu]

If you look at the back of the disc you can see what looks likes the wear limit (the concentric ring on the friction surface). Lets assume thats 1mm. You can see that any further material removal would come from the remaining material.
Its hard to estimate the thickness there but it is clearly not a massive amount to start with.
It surely makes more sense to make the carrier clear the disc rather than modify the disc.

[orsum]

Yep I agree I see your concern.

Pointless getting upgraded brakes fitted if they fail.

Carrier looks like it could be the way to go.

[orsum]

Seems like the CX5 could be the answer I have been looking for.

Looks like a PCD change and away you go, off the shelf.

or not just noticed some not so nice measurements.

[twoqu]

Think Rusty used Madza discs as the basis for his conversions.

[orsum]

Yep I that's correct.

Unfortunately what he uses is costly due to having to import. Cost issue.

Now need to see if these are available in SA.