Need a wheel offset guru!

    I bought a Rohana 20x11 w/ a +48 degree offset for the rear with a 315/35/20. Since I put her on she was squirrelly and I swear she pulls left on acceleration.


    I noticed the tire was not centered so I put on a 1/8 and 1/4 spacer which helped a ton, but I still feel it. The rear end feels like its dancing on the highways.


    Is there some conversion for a 3deg offset in inches or mm for a spacer?? Its driving me nuts. Is there a better way for me to check all of this? I did take a plumb on a string and it looks fairly centered.


    Help!

    I would suspect the tire being the problem before I'd worry about 3 mm offset. If you have a tire with a softer sidewall on the Slingshot it will make the rear end feel a little squirrelly. I had a Nankang NS-20 275/35R18 rear tire that some feel has a soft sidewall and noticed the rear end seemed to respond to any steering wheel movement.
    The 3mm additional offset your wheel has is only about 1/8", so you actually over-corrected for the extra offset. I have a 17 x 10 Mustang wheel with a 315/35R17 Nitto 555 G2 and that wheel only has 28mm offset meaning the wheel sits around 3/4" to the left compared to the stock wheel and I've never noticed a problem with that setup.
    What brand and model tire do you have on that wheel?

    Quote from BKL

    I would suspect the tire being the problem before I'd worry about 3 mm offset. If you have a tire with a softer sidewall on the Slingshot it will make the rear end feel a little squirrelly. I had a Nankang NS-20 275/35R18 rear tire that some feel has a soft sidewall and noticed the rear end seemed to respond to any steering wheel movement.
    The 3mm additional offset your wheel has is only about 1/8", so you actually over-corrected for the extra offset. I have a 17 x 10 Mustang wheel with a 315/35R17 Nitto 555 G2 and that wheel only has 28mm offset meaning the wheel sits around 3/4" to the left compared to the stock wheel and I've never noticed a problem with that setup.
    What brand and model tire do you have on that wheel?

    I agree , a soft sidewall tire would make it feel like its loose. I had that issue with one of my tire choices. I had @TheRock follow me one day thinking my rear was all over the place and it was not. I think you're just feeling the sidewall shifting.

    Quote from deaf1

    I went with a nitto motivo. I had a nitto info on the old stock rim and never felt anything
    Should I go back to a info or ???

    As I wrote earlier, I had already test-driven a Nitto 555 G2 315/35R17 on the rear and never noticed any problems. I also just bought new Nitto Motivos for the front, so I hope they do not have a soft sidewall.


    I had a Sumitomo HTR Z III 295/30R18 on my rear and it, too, is an asymmetrical design. IIRC, it also seemed to have a tendency to want to pull slightly under hard acceleration.


    Overall, Nitto tires seem to have a good reputation, so I hope the problem isn't the sidewall. Technically, the Motivo is an asymmetric tire in that the tread pattern is not the same on both sides of the tire. With two such tires on a normal axle, the different tread positioning should cancel each other out, but since the Slingshot only had one rear tire, you just may be noticing the tread's grip. It would cost some money, but if you had the tire remounted with the the tread pattern flipped so that what was the left side is now the right, you could then test it to see if the tendencies you noticed were still present, but reversed. I hope/think you will get used to how the tire tracks over time.


    Since I only got about 7000 miles out of it, I tried the Nankang NS-20, which as I wrote seemed to feel a little squirrelly in response to ANY steering wheel movement, no matter how small. Strangely, it felt fine during high speed rapid lane changes (rapid left followed by rapid return to right lane). The Nankang NS-20 was actually a little less expensive than the Kenda tires Polaris uses, and is actually a decent tire for the money, once you get used to it.