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Wheel Size - Spacer Fitment Question

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Neveragain55
Bigcoupe 100 Post club
Posts: 152
Joined: Wed Mar 13, 2013 12:58 am
Location: Connecticut

Wheel Size - Spacer Fitment Question

Post by Neveragain55 » Thu Jul 23, 2020 10:03 pm

Hi Gang,

I have a quick question concerning wheel spacer/tire size/wheel fitment.

I’ve made all of my calculations, and I even posted them below as I already know that without this information nobody will be able to give any input.

New BBS Wheel Dimensions:
Front wheels: 18 x 8.0
9 - 1/8th inches total width (9.125) (231.775mm) divided by 2 equals: 115.8875mm
5 ¾ inches (5.75) (146.05mm) from face of hub to end of wheel (30.1625 offset)

Rear Wheels: 18 x 8.5
10 - 7/8th inches total width (10.875) (276.225mm) divided by 2 equals: 138.1125mm
6 - 5/8th inches (6.625) (168.275mm) from face of hub to end of wheel (30.1625 offset)

Old M-Parallel Wheel Dimensions:
Front wheels: 18 x 8.0
9 - 1/8th inches total width (9.125) (231.775mm) divided by 2 equals: 115.8875mm
5 inches (127mm) from face of hub to end of wheel (11.1125 offset)

Rear Wheels: 18 x 8.5
10 - 7/8th inches total width (10.875) (276.225mm) divided by 2 equals: 138.1125mm
6 - 1/4th inches (6.250) (158.75mm) from face of hub to end of wheel (20.6375 offset)

Here’s the short version of my saga……

My M-Parallel wheels bit the dust a while ago and I bought a set of aftermarket, replica BBS RS wheels.
(please no lectures just because I didn’t spend a king’s ransom on real BBS wheels) :-$

I love the wheels and their gorgeous, my issue is that the new wheels have a (if I did my math correctly) 30+ offset which makes the inner side of the tire hit the shock (on the front wheel) and it doesn’t even have enough clearance to bolt on. The rear wheel fits much better but she's damn near right up against the shock.

I purchased a good set of ECS wheel spacers for the rears and the fronts.

I got 12.5mm ECS hub-centric spacers for the rear’s, and 20mm ECS hub-centric spacers for the front wheels.

Once again, if I did my math correctly, the front spacers should be just thick enough to move the inner side of the front wheel off of the front shock, but not enough to make the outer side of the wheel rub up against the inner fender.

I admit I’m not crazy about putting such a thick spacer on the front wheels but everything I’ve read and all of my research tells me that I should be just fine as long as all the parts are quality parts, it gets assembled & torque correctly, and that I don’t go racing the damn thing. (which I’m not)

So to the question............will the 12.5 mm spacers out back work with no rubbing issues (I really think they will), and will the 20mm spacers out front work with no rubbing issues (i'm not so sure about them) given the dimensions I’ve provided???????

It should be noted here that I didn’t need any spacers at all with my M-Parallel wheels and I should have paid much more attention to the offsets when I got the replica BBS wheels but that’s all behind me now, and all I’m interested in is making what I have work.

As usual, thanks in advance…………


P.S. I included pics of the wheels. the pic of the BBS wheel is my wheel, and the pic of the M Parallel wheel is from the internet but it's identical to what I had on the car. They were chrome and gorgeous but the chrome chipped away.......never again.


download/file.php?mode=view&id=31233
download/file.php?mode=view&id=31232
Attachments
M Parallel Wheels.jpg
M Parallel Wheels.jpg (178.83 KiB) Viewed 385 times
BBS RS Wheel.jpg
BBS RS Wheel.jpg (279.73 KiB) Viewed 385 times
1989 635 CSI L6
1977 Datsun 280Z
1994 Acura Legend LS Coupe
1979 Suzuki GS750E
2003 BMW K1200GT

User avatar
Neveragain55
Bigcoupe 100 Post club
Posts: 152
Joined: Wed Mar 13, 2013 12:58 am
Location: Connecticut

Re: Wheel Size - Spacer Fitment Question

Post by Neveragain55 » Fri Aug 07, 2020 9:31 pm

Follow up to my question.....

So as you can all see in the pictures that the wheels are on and (so far) there's no rubbing issues.

I haven't had her on the open road yet but a quick test (turning, braking and going over bumps) in the parking lot of my apartment complex proved successful.

I have good clearance between the inner-side (or back-side) of all four wheels and their perspective shocks, but the outer-sides (face-sides) of the rear wheels are pretty much parallel with the inner wheel-well lips.

So as long as I keep the car at stock ride height I should be fine, I figure if I lower her even a pinch I'll have rubbing issues in the rear.

The outer-sides of the front wheels (even with the massive 20mm spacers) seem to still have a good amount of clearance from the inner wheel-well lips, and in full turn in either direction they don't come close to touching anything.

So, to all those in the future wondering if a staggered set of aftermarket BBS wheels (Rear: 275/40/18 with 12mm spacers, Front, 235/40/18 with 20mm spacer) will fit/work.......I've already don'e your homework, that set up will work.
20200807_164644.jpg
20200807_164644.jpg (293.91 KiB) Viewed 324 times
Happy Motoring......
1989 635 CSI L6
1977 Datsun 280Z
1994 Acura Legend LS Coupe
1979 Suzuki GS750E
2003 BMW K1200GT

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