BMW 4.72 (120mm)

[apex69]

Any good information out there on fitment alterations needed to mount BMW rims which are at 4.72 bolt circle (120mm), to my Chevy's 4.75 (120.65mm)?

[Martin71RS]

Yes... if you do a search in this forum you will find some info... also on my page a lot about ET versus BS and more
http://surf.to/camaro
page 20 I think....
(or close)

as a sidenote, I am selling my BBS's again since I cant get them to fit the way I want... funny thing is ET and wheelsize is allmost identical to my OZ wheels, which are a perfect fit... it also has to do with wheeldesign! I am also going to fit C5 brakes which makes it even harder.

I could have fit the BBS with adapters, but I think they go outboard too much, I like em tucked in. (specially since I will be driving it and I am going to lower it a bit) I also could have milled out the center a bit and have the front axle stick out....but with the C5 brakes it won't clear the caliper then.

so...expensive lesson for me again..on the lookout for other rims again.

Martin

[Twin_Turbo]

remember that bimmer wheels are hubcentric

[apex69]

Martin thanks. Have done some web searches, not much luck. I’ll try a PTGM search.

TT, I am familiar with the need for hub centricity on the bim wheels. Was looking for a possible lead on someone that may have done this and/or have specs/dimensions on this fitment.

Patrick

[Martin71RS]

Patrick, did you see my page? lots of info on specs/dimensions there (with pics even)...what other measurements do you need?

Martin

[apex69]

Patrick, did you see my page? lots of info on specs/dimensions there (with pics even)...what other measurements do you need?

Martin

OOPs, I guess that would help huh I actually have to click on the link. Ok, I got lost in the thread "click"


So the wheel spacer bolt pattern is 5 lug on 120mm X 5 lug on 120mm or dose it convert from the BMW 120mm (4.72), to the Chevy 120.65 (4.75)? What tolerances did you use for the centric ring fitment?


Funny, I'm running a 2:73 posi, 24.5 wheel dia.

[Martin71RS]

Yep, the adapter is bolt pattern 5 lug on 120mm X 5 lug on 120mm.

The tolerances for the centric ring fitment...don't know... I measured the hub (in mm as we do here) and the inside of the wheel and gave those sizes to my stepdad who made me some nice centerrings.

I guess any one who is handy enough to make them will know how much tolerance you need to make it work.

the difference between 4.75 en 4.72 is too small to notice (0.03")....as long as you have a centerring to center the wheel it will work (very good I might add)

hope this helps....
Martin

[apex69]

I will use a 0.1mm tolerance. Tight yes, but not by NASA standards. I'll see what happens on the runout.

I would imagine each ring will have to be made for each individual wheel/hub combo.

Cheers