Yet another wheel question!!

slim2none

slim2none

Dedicated Member
British Zeds
Joined
Feb 12, 2024
Points
26
Location
South Cumbria
Model of Z
Z3 1.9 M44
So I've acquired a set of 17s with 225/50/ZRF17 tyres. Rim size is 7.5x17 IS37.
I tried fitting one on the front yesterday, however the strut hits the tyre....or vice versa!
After looking on here and seeing that people have previously fitted this size tyre without issue, I'm left thinking that it's the offset that's the problem. But my understanding is that a 37 offset would sit further out than the original 7x16 IS46 stock rim with 225/50/16.
The question is, what do I need to do to fit these so there's no contact with the strut, or is this a non starter due to the offset?

As you can tell my head has popped!!
 

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Or do I say screw it...sell these and just put new rubber on the original 16s?
 
Would a set of spacers (say 15mm) stop the tyre fouling on the strut?

Tony.
 
Thanks Tony. That's really what I'm wondering. Not sure how much that will affect the poke at the arch.
I'm going to refit again this afternoon (and take photos this time!), to get a better understanding of the situation.
Just wondered if anyone had already come across this same issue and resolved it.
Hope to get it resolved coz they look great on the car!
 
slim2none said:
So I've acquired a set of 17s with 225/50/ZRF17 tyres. Rim size is 7.5x17 IS37.
I tried fitting one on the front yesterday, however the strut hits the tyre....or vice versa!
After looking on here and seeing that people have previously fitted this size tyre without issue, I'm left thinking that it's the offset that's the problem. But my understanding is that a 37 offset would sit further out than the original 7x16 IS46 stock rim with 225/50/16.
The question is, what do I need to do to fit these so there's no contact with the strut, or is this a non starter due to the offset?

As you can tell my head has popped!!
Click to expand...

Your 16 and 17 wheels both have 225/50 tyres. Tyres are the same profile. That means your new 17 setup has an overall 'taller' wheel. The whole thing is an inch taller (half inch more above the hub)

What part of the strut is it touching? The base of the spring? What's that plate called that the bottom of the spring rests in?

As tony said, spacers would bring the whole thing outwards. But if it's the height of the wheel that's touching the base of the spring then maybe go for lower profile tyres to get the overall rolling radius back the same as it was
 
Yes, bottom of spring plate sits on tyre.
I know the whole diameter is an inch up from stock, but hoped the offset was going to solve any clearance issue.

Is there that much difference in height of the 45 & 50 profile? I suppose there must be.

I figured I'd need the recommended 45 profile tyre at some point but the 50s that are on the rim have loads of meat on them and being a cheapskate hoped I could just run with them. 😉
 
Ditch them and get the correct ones.
Normally this setup would not pass TUV (no idea about MOT).
 
What has TUV got to do with a car in the UK?

Tony.
 
. . .
t-tony said:
What has TUV got to do with a car in the UK?

Tony.
Click to expand...

I think he's saying that if the car was in germany it wouldn't pass TUV

In germany your log book contains the wheel and tyre size that the car was supplied with. Also the little reg card that should always be carried by the driver has this info. So police can ask to see that card and then look to see if the car has the original size tyres.

You can change wheel and tyre sizes as long as it's to a size authorized by the OEM. And have the logbook and reg card updated to include the new size.

To answer @Zephyr 's question. In the UK we can do almost anything we want with our wheels as long as they're contained within the wheel arches.
 
Yes, I know what the TUV is and how anal they are in Germany about s*** like that. I just didn't get the relation between that and a car used in Cumbria, that's all.

Tony.
 
t-tony said:
Yes, I know what the TUV is and how anal they are in Germany about s*** like that. I just didn't get the relation between that and a car used in Cumbria, that's all.

Tony.
Click to expand...

Absolutely none.
If you had similar rules to the German ones, it would.
 
Just for reference to avoid problems like this:

www.willtheyfit.com

Play on there BEFORE buying new wheels and tyres, not after! ;)
 
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slim2none said:
is there that much difference in height of the 45 & 50 profile? I suppose there must be.
Click to expand...

Yeah......5 :thumbsup:

The profile is a percentage of the width. So a 225 wide tyre with a 50 profile is 50% of 225mm = 112.5mm. That is the wall height of the tyre (x2 plus rim diameter)
A 45 profile on a 225mm width tyre is 225mm x 45% = 101.25mm. So roughly an inch larger diameter, which is why you drop the profile when you go up an inch in wheel diameter.

Changing the rolling circumference of wheels by much is not a good idea, as it affects many things on modern (ish) cars. The speedometer will be out for a start, let alone the impact on DSC/ ASC control.
 
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But we don't. End of. Do you, in Greece?

Tony.
 
So why mention the German TUV and not what you have in Greece?
 
Pond said:
Just for reference to avoid problems like this:

www.willtheyfit.com

Play on there BEFORE buying new wheels and tyres, not after! ;)
Click to expand...

Thanks for the reply. I had checked a couple of places and on here where people had fitted the same sizes to their own Zs.
It looks like the wheel/tyre combo should fit and be clear of suspension doesn't it?
 

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Try 225 45 17 tyres,
This is the standard and correct tyre size for a Z3 front tyre, when fitted with 17" wheels.
 
Hope nobody minds me waking up this thread.

My car has the bog standard struts on the front. Big spring base plate just above the tyre.

I want to try taller tyres. It's a 507 rebody and I want to see what it looks like with taller tyres. But there's not much room below the spring base.

My question. If I went for adjustable coilovers they look like they don't have such a big spring. Would I be right in assuming that I can go for taller tyres without touching the strut?

Yes. I know taller tyres will change the diameter/rolling radius but that's a different topic for another day.

Thanks guys.
 
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