* 18" 930 RUF wheel fitment/tire size

[Craig 930 RS]

http://www.weissach.com/item-details.asp?itemID=190&itemType=partsInventory


Called Weissach in Canada - the 18s are 8.5 & 10 inches F&R.
The wheels are provided with spacers.

Thing that gets me is the tire size they list for those wheels are 225 and 265! Pretty narrow for that size wheel.

Are the spacers for RUF wheels sized so that the 225s and 265s are about as big as one can fit, or is RUF playing it conservative with the tire sizes? I'd like to install 245 & 275 or 285 rear.

THX!

[Randy Blaylock]

To my knowledge, only Pirelli makes a 245/35-18, which would be the ideal size, otherwise it's a 235/40 to keep the O.D. within an acceptable range. A 225 is too narrow and stretched on a 8.5 so the sidewalls really take a beating. I run 235/40-18 S03s on Natalie's car on the 8.5 inch front, and 285/30-18 on the 10 inch rears. This is on a "narrow body" 993 for what that's worth.

[Miguel Antonett]

You should be able to install 245 & 285 on 8.5" & 10" wheels with no problem. The fit up on the car is a different story, but you should be able to fix that with the right spacers.

[Thunder Punk]

I'm curious about this as well. I've got a set of 19X8.5 and 19X10 ready to mount but I'm trying to determine exactly what tire size to mount.

It was suggested that I use a 245 0r 235/35/19 for the front and 275/30/19 for the rear. I would imagine that this would be ok for your application as the only thing that would be different would be the aspect ration because my wheels are 19" instead of 18".

Using the tire calculator here http://www.miata.net/garage/tirecalc.html It suggests that I use 245/30/19 for the front and 275/35/19 for the rear if I want to keep the speedo accurate.

Here's a pic of a 930 with the 19s mounted. This is using the suggested wheel sizes by the manufacturer and not the calculator.



I'd like to go with a 285 on the rear if I can using the factory spacers. And I'm not sure how wide to go on the front. I don't want to get into rolling fenders or anything of that nature. Any help would be truly appreciated.

[rdane]

Gotta remember RUF spends a huge amount of time working/thinking/going very fast on the Autobahn and not all that worried about how much tire he can get under the car to make turns in 3rd gear.

Hitting 220mph+ means skinny tires and low Cds.

[Bill Verburg]

It would be really helpful to provide all of the pertinent info.

o/s and spacer width for a start

[Craig 930 RS]

It would. The rep didn't know the RUF offset & spacer size.....hence my size concern. One would think that Weissach would know -

OK called again and talked to Andrew at Weissach.
"225/265...the biggest you can fit. Not made for 18s. No way"
Okaaay.

Offset front: "ET 58"
Offset rear: "ET 68"

Spacer size front: 28
Spacer size rear: 35
---------------------------------------------------------------------------
I found BFG T/A KD in:

225/40/18
245/40/18
265/35/18
265/40/18
275/40/18
285/30/18

In 245F/275R - the front would be a tiny bit shorter (98mm vs. 102mm), and the rear virtually identical compared to the 255/40/17F & 315/35/17R, correct?

What conclusions can you drawy, RB and VB as to what size tire I can truly run, given the info above?

TIA

[}{arlequin]

Originally posted by Randy Blaylock
To my knowledge, only Pirelli makes a 245/35-18, which would be the ideal size, otherwise it's a 235/40 to keep the O.D. within an acceptable range. A 225 is too narrow and stretched on a 8.5 so the sidewalls really take a beating. I run 235/40-18 S03s on Natalie's car on the 8.5 inch front, and 285/30-18 on the 10 inch rears. This is on a "narrow body" 993 for what that's worth.

is there *any* way that you could post more pics of the vader mobile??

[Craig 930 RS]

The motivation behind the 18s are that I can't find 17" RUF wheels in 9/10 anywhere - Leo had a set but decided to keep them.

I've a long time Jones for the RUF wheels

[Bill Verburg]

Ok
net o/s in the front is +30mm
net o/s in the back is +33mm

To compare w/ the current setup, we need to know what is there now, wheel width, o/s and spacer thickness

[89911]

Unless you've got an extreme Ruf hankerin or getting a great bargain, your getting a heavy wheel that isn't wide enough for your car. Order some custom Fikes's and be done with it.

[arrivederci]

Originally posted by 89911
Unless you've got an extreme Ruf hankerin or getting a great bargain, your getting a heavy wheel that isn't wide enough for your car. Order some custom Fikes's and be done with it.

Agreed. The RUFs are heavy and you're using spacers. Fikses would solve all of that...

[Bill Verburg]

Agreed. The RUFs are heavy and you're using spacers. Fikses would solve all of that...

Double agrees, or Kinesis

[Craig 930 RS]

That was a point of consideration.

I saw a set of 8 & 9 RUF wheels for 2k, a set of 9 & 10 for 2.7k, (both unavailable/sold now) and then new set of 8.5 and 10 RUFs for......$3,300.

That is easily custom wheel territory.

I love the look of the RUF wheels on a 930. They would be for street use only with the Kinesis for track use. But $3,300 for a cast wheel set?

[arrivederci]

I'm not sure what Fikse/Kinesis go for these days, but I paid roughly $800 per wheel for 8.5's and 10's that are on my 930. They needed no spacers (other than the factory ones). I could've gone wider, but didn't want the hassle of having to grind bolts, move hoses, etc.

[Randy Blaylock]

The Ruf 18 inch wheels are not the same beast as the 17s.

I don't have the raw numbers, but when I was carrying mine around to get the tires mounted I was surprised that they are actually fairly lightweight. Certainly not a margin worth considering, particularly in the application Craig is intending.

They are very easy to clean, unlike the nightmare most three piece wheels are. For what that's worth.

245/40s are too tall in my opinion, a 245/35 is optimal, but as I said earlier, Pirelli is the only decent tire to my knowledge. There are countless 235/40s that will work. A 285 on the 10 inch rear would be a good size.

Finally, the wheels are currently on sale for $1995 Cdn, which is a great price for a very stylish wheel.

Personally, I don't care for the look of 18s on early cars, and the price distinction between 17 and 18 inch tire prices is large enough to give me pause. Using spacers is a pain when swapping wheels for track/street use, but it's not my car and my labor so who cares what I think?

[Craig 930 RS]

Ease of cleaning is a big point for me. The Fikses can be such a PITA to clean. A friend sold his set for that very reason.

Randy - Are the 17s or 18s on sale? I didn't know that. $1,995 is a great price -

[Randy Blaylock]

Oops, typo, it's $2995 CDN. What's the current exchange?

[arrivederci]

Just an FYI - the FM-5 isn't tough to clean. Other than the non-painted surfaces having the potential to show water spots, it shouldn't be any more difficult than any other 5 spoke wheel.

[Jeff Alton]

Craig, if you need good info when calling Weissach, talk to Stewart. He is actually the service manager but he knows his stuff.....

The kinesis are hard to keep clean, at least the K27 sure is!

Jeff