Group buy brake discs question center bore

boomerang

Member
Messages
412
A few years back I bought a brake disc set for my Gransport in our group buy at that time.
Now, while reconditioning the front suspension, I wanted to mount them at last.
But, when I put the disc over the centering “nose” of the wheel bearing, I notice that the center bore diameter of the front discs, is a tad too large.
It is not the tight fitting I experienced with the original discs.
Even with a brand new wheel bearing, this centering problem occurs.

Did you guys notice this also?
I think there is a 0.08-0.09m slop.
Did they correct this in the course of time maybe?
Problem is that these heavy discs, when not centered perfectly, will cause some imbalance itselve.
 

midlifecrisis

Member
Messages
16,264
A few years back I bought a brake disc set for my Gransport in our group buy at that time.
Now, while reconditioning the front suspension, I wanted to mount them at last.
But, when I put the disc over the centering “nose” of the wheel bearing, I notice that the center bore diameter of the front discs, is a tad too large.
It is not the tight fitting I experienced with the original discs.
Even with a brand new wheel bearing, this centering problem occurs.

Did you guys notice this also?
I think there is a 0.08-0.09m slop.
Did they correct this in the course of time maybe?
Problem is that these heavy discs, when not centered perfectly, will cause some imbalance itselve.
I've never noticed that on my old 4200, Luuk. they seemed to line up Ok but it was about 5 years ago when i fitted them, so memory is a bit dim... check MAF's disc changing thread here...
https://www.sportsmaserati.com/inde...cs-and-pads-3200-4200-spyder-gransport.17743/
 

Zep

Moderator
Messages
9,317
I think that is pretty close to what everyone else call a perfect fit. Dirt on the OEM disc could take that up.