Monaro wheel centre bore? Definitive answer?

[Lincsls1]

Hi guys.
Can anyone tell me the precise answer to the question?
I've searched and found several answers...
69mm
69.1mm
69.5mm
69.6mm (this one quoted by the wheel shop LK performance).
70mm


I found this for the Pontiac GTO which is surely the same...

https://www.wheel-size.com/size/pontiac/gto/2004/
Last thing I want to do is spend good money on new wheels n tyres to find they don't fit and/or cause vibrations.
I'm looking to buy some BBS wheels which have a CB of 82mm so will need appropriate spigot ring to adapt.
Ta...

Edited by Lincsls1 on Saturday 15th September 13:46

[Aitch H]

I had wheels supplied by LK Performance on my 1st Monaro and they’d bored the centres out to their measurements and I didn’t have any problems with vibration or anything so I’d go on their measurement when ordering spigot rings if I was you, and besides the maximum difference on all the measurements you’ve got is about 0.5mm from 69.1 to 69.6 or a whole 1mm if that 70mm measurement at the end is relevant. I would have thought that the hubs must expand and contract by more than that under normal driving and weather conditions anyway so can’t see it being a problem

[Lincsls1]

Aitch H said:

I had wheels supplied by LK Performance on my 1st Monaro and they’d bored the centres out to their measurements and I didn’t have any problems with vibration or anything so I’d go on their measurement when ordering spigot rings if I was you, and besides the maximum difference on all the measurements you’ve got is about 0.5mm from 69.1 to 69.6 or a whole 1mm if that 70mm measurement at the end is relevant. I would have thought that the hubs must expand and contract by more than that under normal driving and weather conditions anyway so can’t see it being a problem

Very interesting mate. Thank you. I was also wondering just how much 0.5mm difference would make and can't see it being an issue myself.

[fred bloggs]

Lincsls1 said:

Very interesting mate. Thank you. I was also wondering just how much 0.5mm difference would make and can't see it being an issue myself.

0.5 mm will be an issue, and you will have a wobble.
I know this may be a silly suggestion, but why not just measure it ?


I had some ally spigots made, I believe they were 69.1 mm ,but don't take anyone's word, measure it.

[Lincsls1]

I will. Bought a cheap digital vernier caliper to do just that.

[Lincsls1]

Updating this for future reference purposes....
The alloy spigot rings provided directly from BBS with my new wheels are apparently 69.6mm, fit very snuggly and I haven't encountered any wheel wobble across a large range of speeds.
That said the wheel bolt holes are also lug centric (tapered) so theoretically when tightening up should self align.

[Steve_T]

I had some Work Wheels made for me a while back (they're Emotion CR Kais), these were 69.6 centre bore and have a precise fit with no spigot rings needed. Offset was very close to standard at ET47 with the standard 5x120 PCD (also BMW fitment).

HTH,
Steve