Contour Enthusiasts Group Archives Forums Modifications Wheels & Tires OffSet

I am running 17 x 7 (37 offset) zero problems
I am considering going to a 17.7.5 (35 offset) any feedback?

I'm on H&R with stock struts now, but will have Konis for the new wheels.

Mark

EDIT:

ive read back through 10 pages of dialogue. It seems that this wont work, ~40 is the lowest people say, yet I am running 17 x 7 (37offset) with out issue on my OZ SuperT's? Will the 2mm cause me a problem? I've also looked under the car, but realized I had my winter set on, doh! Also, I have lightly rolled my lips. I could roll a bit more if needed.

Looking for input in a time sensitive issue. TIA...

OK: 7" and 37mm offset means 125.9mm or 4.96" of the wheel are inside the mounting surface. ((7in x 25.4mm/in) / 2) + 37mm = 125.9mm
Therefore: 7.5" and 35mm offset will mean 130.25mm or 5.13" of the wheel will be inside the mounting surface. ((7.5in x 25.4mm/in) / 2) + 35mm = 130.25mm
Do you have an additional 5mm clearance between the tire and strut tower? If not you'll need 5mm wheel spacers. Be sure of this - see my posts under, "Help! My Tires Self Destructed."

I am looking at adding 15mm spacers just to be sure.
Original E1 wheel: 6.5" and 40mm give 122.55mm
My Alba Blaze: 7.5" and 42mm give 137.25mm
137.25mm - 122.55mm = 14.7mm
15mm = .59" or between 9/16" and 5/8"

I'm hoping they don't stick out too far...

Martin

I'm not sure if Martin did all of his math right, but he has the right idea.

So peep this page http://www.tirerack.com/wheels/tech/offset.htm

Let's see what I can come up with.

Off to play with Star Office a bit.

TB

I've plugged in a few numbers and with your 37mm offset I get the following on a 7" wheel

Width outside the hub = 51.9mm
Width inside the hub = 125.9mm

If you go to a 7.5" wide wheel with a 43mm offset, I think you get 52.25mm outside the hub and 138.25 inside.

Staying at the same 37mm offset, but with a 7.5" wheel nets you 58.25 outside and 132.25mm inside the hub.

I dunno which way you need to go though.

TB

Now hopefully with math errors corrected

Yes, I did the math right. Yours is obviously wrong.

Your numbers don't add up: 140.8mm outside the hub + 214.8mm inside the hub = 355.6mm which is 14"! He is talking about 7" wide wheels not 14" wide.

Martin

You are right, I found I missed the division by two. I was just curious how you got the same width on both sides with a non-zero offset. I'll edit my message above, if I still can.

Thanks,

TB

(EDIT: Never mind, I misunderstood your original message. I'm glad I'm not working any service calls right now, I can't even understand basic english or math.)
tb

Check your entering arguments. I don't think 40mm is the stock offset for the E1 wheels. Somebody said 49.5mm the other day, but I don't have first hand knowledge, here.

As for me, I'm running 7.5" 16's with 43mm offset, and I'm OK. HTH.

40mm is the offset for the stock 16 x 6.5" E1 wheel. The 17 x 7" Focus SVT wheel has a 49mm offset.

If the E1 wheel was 49mm I would have had no problems with my 18 x 7.5" wheels with a 42mm offset.

Martin

OK. Thanks for clarifying.