Wheels & Tires - Can someone help me figure out my wheels offset?

Hey guys I did the math, but would like someone to double check. Also will they fit my TA?

They are Fikse FM5s

17x9.5
BS 7 3/8"
centerline is 5.1875

17x11
BS 8 3/8"
centerline is 5.9375

My results are

17x9.5 55.5625 or 56mm
17x11 61.9125 or 62mm

I am making sure the offset is correct before I mount the tires.

Thank you for any help.

Bob s.

Can anyone give me a hand?

bob s.

why do you need to know offset? It is a poor comparison to other manufactures specs. It is not standardized. Don't use it...It will get you close, but why bother.

Backspace is your best reference...by your numbers, the fronts are going to be "ok", the rears will tuck in a bit too much, you'll have issues with the inner fender and component interference.

Steve.

You have a PM

Bob S.

Steve I see you don't except PMs. Are my calculations right? Man I hope this aint true :(

Bob s.

I come up with the same offsets as you do going by your given CL and backspacing numbers.....

according to the FAQ part of this forum:

what will fit on the rear:
11.0" wide rim ... +45 to +56 mm .... 305, 315, 335

what will fit on the front:
9.5" wide rim ..... +38 to +56 mm .... 255, 265, 275, 285

What are the wheels from?

Steve why do you feel offset is not a "standardized" way of specifying wheels . . . :confused:

Fronts calculate out to around 55.37 mm
Rears calculate out to around 61.72 mm

I am going to guess these are from a Corvette . . .

Fronts will fit like a stock SS or WS6 wheel, rears will need a spacer to mount.

The wheels could always be sent back to Fikse and re-hooped to fit and F-Car.

why do you need to know offset? It is a poor comparison to other manufactures specs. It is not standardized. Don't use it...It will get you close, but why bother.

Backspace is your best reference...by your numbers, the fronts are going to be "ok", the rears will tuck in a bit too much, you'll have issues with the inner fender and component interference.

Steve is right, you will be ok with this fitment. You're going to be cutting it close in the rear (no tolerance for tire bulging), and may have some component interference up front.

For your reference, our recommended backspacing for your application up front is 6.08", and out back is 7.58". Good luck!

Danny G.

What are the wheels from?

Steve why do you feel offset is not a "standardized" way of specifying wheels . . . :confused:

Fronts calculate out to around 55.37 mm
Rears calculate out to around 61.72 mm

I am going to guess these are from a Corvette . . .

Fronts will fit like a stock SS or WS6 wheel, rears will need a spacer to mount.

The wheels could always be sent back to Fikse and re-hooped to fit and F-Car.

:thumb: :judge: A C4 as a matter of fact! Good work...

:thumb: :judge: A C4 as a matter of fact! Good work...
Actually very scarey the stuff I've learned from you guys. :)

I have a set of BFG KDs so I will need extra bulging room lol. grr I am not having luck with getting me some wheels.

Bob s.

Well what do yall recommend.
1. Can he mount these with 315 35 17 KD's on his T/A
2. Will he require a spacer and if so is there any safety concerns? I have just done some research and could not find any safety concerns.
I sold these wheels to 1badbird. I was going to put these on my firehawk and circumstances did not allow this to take place and pics are on this thread also. Thanks guys for all yall's help and Bob is a great guy!!!!
http://www.ls1tech.com/forums/showthread.php?t=663345

Well hey there RIck!!! KDs are one of the widest 315s out there according to tirerack. Just concerned about the offset, and want to be sure before I mount the tires. We have experts here :)

BOb s.

Hey Danny! Good to see you're involved on the forums. To answer above...spacers can be used, be cautious of the amount that is used. You don't want to move your sheer line out too far on the studs.

Bead to bead measurement can vary. Use backspace, don't bother with conversions.

Well hey there RIck!!! KDs are one of the widest 315s out there according to tirerack. Just concerned about the offset, and want to be sure before I mount the tires. We have experts here :)

BOb s.
Well my top priority is for you to be happy and safe. I'm sure they will be good to go. These guys sound like they know what's going on and so do you. :lurk: