help w/ a 930 front rotor measurement

[Bill Verburg]

Anyone have either a '78-80 930 floating hat/rotor or an aftermarket 304x32 rotor w/ non floating flat hat off the car?

I'm looking for the distance from the hat mounting face to either the rotor centerline or to the back face of the rotor. Either will do, the latter is easier to measure.

This measurement will do

[Bill Verburg]

bump

[tijnes]

Bill

Are the front rotors in the pic the ones your looking for? If so let me know, I'd be happy measure it this afternoon or latest tomorrow.

[Bill Verburg]

Originally Posted by tijnes

Bill

Are the front rotors in the pic the ones your looking for? If so let me know, I'd be happy measure it this afternoon or latest tomorrow.

yes, those wil do.

try to be as precise as possible, a mm +/- makes a difference

TIA

[group911@aol.co]

Bill, as measured from the back side of the rotor to the back side of the hat adapter, I came up with 29.60 mm. The one variable is the thickness of the rotor and I forgot to measure mine but it is pretty close to full. Pic should show where I measured. Let me know if you need another measurement.
Thanks for all your work on these brake systems.
Bob

[Bill Verburg]

Thanks! that's a great start

those look like the factory floaters?

[group911@aol.co]

They are factory.

[Bill Verburg]

~1mm/side of wear on the rotors?

[group911@aol.co]

I'll try to get an exact measure.

[tijnes]

Bill

I used the same method as group911 and come out to 30.2mm. The thickness of the rotor is 31.7.

Martijn

[Bill Verburg]

Originally Posted by tijnes

Bill

I used the same method as group911 and come out to 30.2mm. The thickness of the rotor is 31.7.

Martijn

Thanks, this all helps.

The more data the better.

[Bill Verburg]

the factory spec for the '78-80 930 front floating rotors is 35.7+0.25-0.35mm. measured from the brake flange bearing surface on the hub to the rear friction face(as pictured above)

for the later '81 up it is 56.7+/-0.1mm

the later rotors have greater o/s because the 21mm spacer that is a separate part on earlier car is incorporated into the later 1 piece rotors, these would not one would assume -yes
used w/ SC/Carrera fenders.

[jcge]

Bill - do you have the pitch circle diameter (PCD) of the 12x rotor mounting bolts

I'm ultimateley after the machining dimensions of RSR style hats....so any other relevant dims would be greatly appreciated

John