Front wheel rubbing :(

jeffers said:
I've done some forum stalking and found a comment by the previous owner which suggests the wheels are... 9 1/2 et 42

Does that make sense? I don't really understand wheel sizings
Click to expand...

A 9.5 front wheel et 42 :o that really should be the back but if you are right then that would explain your problem .
In comparison to standard 8j et47 front you would have a rear face 15 mm closer to suspension & outer face 25mm out .

What tyres are fitted on front & rear ?
 
jeffers said:
Ah, my mistake, that's the rear offset. Tyres on the front are 225/40R18
Click to expand...

The pic i linked above if you say are 225 40 18 tyres that would suggest 8j possibly 8.5j ? et 35/42 so not completely wrong for your car .
You really need to remove one to get the exact numbers
Sometimes the sound of scrubbing can sound worse than it is & a matter of a few mm here or there can eliminate it
Are the rear tyres wider or a "square" set up ?
 
That front wheel is 8.5j without a doubt. Definitely not 8j as 8j is standard size, hence why you can see the tyre is stretched.
 
mr wilks said:
jeffers said:
Ah, my mistake, that's the rear offset. Tyres on the front are 225/40R18
Click to expand...

The pic i linked above if you say are 225 40 18 tyres that would suggest 8j possibly 8.5j ? et 35/42 so not completely wrong for your car .
You really need to remove one to get the exact numbers
Sometimes the sound of scrubbing can sound worse than it is & a matter of a few mm here or there can eliminate it
Are the rear tyres wider or a "square" set up ?
Click to expand...


Rears are 255/35R18
 
OK, I have managed to sneak a mirror behind the spokes on the front wheel and grab a picture of the offset. Its 18 x 8 1/2J..

2015-07-21%2019.52.09-2.jpg


So is this the likey cause of my problem, the 8.5j?
 
jeffers said:
OK, I have managed to sneak a mirror behind the spokes on the front wheel and grab a picture of the offset. Its 18 x 8 1/2J..

2015-07-21%2019.52.09-2.jpg


So is this the likey cause of my problem, the 8.5j?
Click to expand...

The offset will be on another spoke , look for a number with "et" before it
 
Nope, checked all the spokes. Nothing with "et" that I can see. Some of the other spokes have what I assume to be weight related stuff on them (KG)...

2015-07-21%2019.55.50.jpg


Any ideas?
 
I'd take the wheel off and have a good look on the back of it, the ET will be printed on them somewhere possibly on the hub face.

Worth looking at one rear too as seeing what the size/offset is
 
Worse case if there is no number stamped ( which is very unlikely) you can work out the number yourself once wheel is off .
Can you see where in the arch liner is rubbing ?
 
OK, so google may have found it for me. Googling "bola b2 bmw z4" eventually brought me to an eBay item which lists the spec as...

BRAND:
BOLA
MODEL:
B2
COLOUR:
GLOSS SILVER
WIDTH(s):
8.5J FRONT-9.5J REARS
SIZE:
18"
OFFSET:
38 FRONT - 42 REARS
FITMENT(PCD):
5x120
STYLE:
SLIGHT CONCAVE STAGGERED 5-SPOKE


That says the front offset is 38. I found a 38 on the back of one of the spokes, just no mention of et...

offset.png


So is a 38 offset bad? No idea with this stuff, give me a computer any day!
 
38 is fine so its either the drop on the springs or the tyre profile & you say 225 40 is the front size so i'm struggling to see why you would be having the issue as many others have dropped their Zs & fitted similar offset alloys or spcers on standard ones :?
Can you see where the rubbing is ?
 
That mark you have posted does t look like 38 offset to me looks like 3/8 I'm not sure but I would imagine it to be written as 38. I would still whip the wheel off and have a look around just to be sure before you spend any money trying to fix the issue.
 
Not good & needs sorting , that would really annoy me a lot :cry: so its either take the ride height up , switch to narrower wheels or tyre a narrower tyre on same wheel ?
 
hopz121 said:
That mark you have posted does t look like 38 offset to me looks like 3/8 I'm not sure but I would imagine it to be written as 38. I would still whip the wheel off and have a look around just to be sure before you spend any money trying to fix the issue.
Click to expand...
I've dropped Bola an email to see if they can clarify before I go to a garage on the way home. I couldnt get the wheel off with hand tools and havent got any big breaker bars.

mr wilks said:
Not good & needs sorting , that would really annoy me a lot :cry: so its either take the ride height up , switch to narrower wheels or tyre a narrower tyre on same wheel ?
Click to expand...

yeah, its spoiling the car a little bit for me at the moment. Trying to avoid speed bumps, not opening her up on anything but a dual carriageway.

So - the consensus is that with the wheels, tyres and suspension that I have there should not be any rubbing problems?
 
Just get the wheel off and all with be revealed. As i said, it will most likely say 'ET' followed by a number. That number is your offset.

alloyOffset4.png
 
OK, today's update - there is no "et" stamps on these wheels. I couldn't find anything and emailed the manufacturer and they have said:

these wheels would have been custom drilled before dispatch so there would not be an offset marking on them
Click to expand...

They are trying to find the original order details with the offset but I don't fancy my chances to be honest. I have also asked the previous owner if they have any more info.

Next, I have measured with a makeshift plumb-bob the distance down from the top of the arch to the lip of the rim, like this...

2015-07-23%2018.15.11.jpg


The wheel pokes out ~5mm more on the passenger side than on the drivers side. The drivers side does not rub. Even with my DIY measuring I dont think there should be that much of a difference. Looking at it, there appears to be a visible difference either side. So either the wheels are different offsets (unlikely, I would hope!) or the wheel geometry is way out with more camber on the one side.

Is there anything else I can check? I'm very to getting the 108's refurbed and back on and the whole thing realigned!

Thanks for all the help so far.
Jeff
 
Take the wheel off & find the ET number yourself to within a couple of mms .
Easier to watch this than me try to explain how to do it https://www.youtube.com/watch?v=BAxJBWUM9Jo
 
Previous owner is pretty sure the fronts are et 38, same as the ones listed on eBay. I'm sadly lacking a big breaker bar at the moment and cant budge the nuts. Its fair to say they are et 38.

The previous owner said that the geometry hasnt been done since the eibachs were fitted so I'm wondering if thats part of the problem.
 
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