OEM stretched tyres

[golfgeezer]

 

[Zulu4]

I'm struggling to follow what's happening here.
Are the centres different between the 8J and 8.5J 108 wheels ?

 

[golfgeezer]

So just took the passenger side wheels off and as suspected they’re making more sense.

Front passenger side which should be 8x18 has this measurement from inside spoke to lip on rim 6.75”

Rear passenger side 8.5 x 18 measures 7.25” from those points which is how I’d expect them to be so looks like the 5 spoke centre piece on the drivers side got mixed up after they were refurbished

 

[Cornwall1888]

I have the same set up in summer, 225 are more ‘stretched’ but not in a bad way, in winter I have 225 and 245 they fit the same.

Nothing to worry about.

 

[mr wilks]

Remove the bolts , swap the centres , re fit the bolts :?

 

[golfgeezer]

Remove the bolts , swap the centres , re fit the bolts :?

Yes will be doing that once I get the right socket bit for the bolts. Will need to swap the tyres back round again too. Every day is a school day.

 

[mr wilks]

Remove the bolts , swap the centres , re fit the bolts :?

Yes will be doing that once I get the right socket bit for the bolts. Will need to swap the tyres back round again too. Every day is a school day.

If you need to borrow a 12 spline bit I have one .
Its 70mm long & works far better than the 25mm ones .

 

[golfgeezer]

Thanks for the offer Andy but I’ve had a root around in the garage and found a socket bit set I forgot I had so I’m sorted.

 

[Mister T]

I'm struggling to follow what's happening here.
Are the centres different between the 8J and 8.5J 108 wheels ?

Yes they are, and the width markings are on the centres not on the barrels.

 

[Raj_UK]

I'm struggling to follow what's happening here.
Are the centres different between the 8J and 8.5J 108 wheels ?

Yes they are, and the width markings are on the centres not on the barrels.

Besides the width stamp are they different in any other way?

 

[Mister T]

I'm struggling to follow what's happening here.
Are the centres different between the 8J and 8.5J 108 wheels ?

Yes they are, and the width markings are on the centres not on the barrels.

Besides the width stamp are they different in any other way?

Someone who's split them and had them side by side will have to chime in, but I wouldn't be surprised if at least the offset was slightly different.

EDIT: Quick calculation suggests that the rear centres should be about 3.5mm taller between the hub mounting face and barrel mounting face.

 

[Flyingfifer]

Wait so the only marking on the wheel to define its dimensions is on a removable part...? Thats absolutely wild

 

[enuff_zed]

I too have to admit to slightly losing track at one point.
My thoughts right now would be, all the tyres off, split the wheels as required, pair them all up properly and then refit all four tyres.
Unless you're copious post-it notes save some of that effort

 

[brillomaster]

its a shame BMW didnt put a poka-yoke in to prevent you fitting a front centre to a rear outer for example. something simple like a locating dowel only on the rears or something. I know the Nissan 350Z does exactly that to prevent you from installing the larger rear wheels on the front of the car accidentally.

but then again, BMW probably didnt think that anyone would ever need to separate the wheels, and that they would stay corrosion free forever...

 

[sars]

That’s wild and rather surprising, the width, offset and/or part number are cast in so you would have thought they could have made it fit specific so that it was impossible to get a mismatch

 

[golfgeezer]

I agree completely. The 108’s are quite a common wheel to be refurbished so I can’t be the first person this has happened to......can I? :?

 

[mr wilks]

The rear centres can be distinguished from the fronts simply by the depth of the bolt hole , its only 4mm / 5mm but they are deeper on the rears .