Will changing the tire size prevent rubbing on the rear quarter lip?

Discussion in 'The Hides' started by newandold, Jul 18, 2013.

  1. newandold

    newandold Member

    Hi,
    I finally had my Hotchkis lowering springs which I've had for months installed. The drop was 2" all around and he car looks and handles much better but of course something else is now in need of fixing. The rear tire sidewalls are rubbing the quarter panel lip when ever the car hits a bump. I know this could be fixed by changing rims with better back spacing. What my wallet would prefer me to do is simply change two tires. One opinion given to me by a tire salesman was that the size tire I am thinking of changing to will not provide enough clearance during cornering. My Rear tires are 245/60/r15 and 235/60r14 front and all are BFG Radial T/A's.
    My question is this: Will switching the rear tires from 245/60r15 to 235/60r15 provide to prevent the lip and tire touching each other while driving?
     
  2. DaWildcat

    DaWildcat Platinum Level Contributor

    Tough to say. What year/make/model are we talking about?

    If your car is a four link rear suspension, excessive lateral movement when cornering is a symptom of worn control arm bushings, so the rub you get during a straight line jounce/rebound could get even worse when you hit a bump or dip when cornering. a 10mm decrease in section width (5mm on each side of the tire) probably isn't going to make a significant difference, especially when body roll comes into play.

    Devon
     
  3. newandold

    newandold Member

    Thanks for the quick reply.
    The car in question is a 72 Skylark.
    As the car sits without the rear tire and the lip do not have contact. A wear line is forming on the tire about an 1 inch thick starting just below the writing providing the treadware information is written.
    My thinking was that while the tire is narrower it will also slightly shorter and when combined will provide the clearance vertically. I hadn't considered the lateral portion inititally.
     
  4. sean Buick 76

    sean Buick 76 Buick Nut

  5. Doo Wop

    Doo Wop Where were you in '62?

    "Being lowered you should still be able to fit a 275/50R15 without any issues on the right rim (15X8 with 4.5" backspace)."

    Very true. That combo suits '70-'72 rather nicely. With 235s or 245s on the front gives a great stance too.
     
  6. 70 gsconvt

    70 gsconvt Silver Level contributor

    I would have to agree with above. I run a 325/50R15 tire on a 15x10 wheel with 5.625" BS. I did roll the top of my fender lip, and I have no rubbing issues. I think you need to look at your control arm bushings first and make sure they're not 40 year old pieces of rubber. You can also put airbags in the rear springs. I also have them. I just keep about 6-8 lbs. of pressure in them. It's just enough to take a lot of bounce out of the back without really affecting the ride quality. The car no longer is like riding an ocean wave when going over a whoop-tee-doo on the highway or other big bump in the road.

    Try these two solutions first before buying new wheels. They're both cheaper and should solve your problems. Good luck.

    Of course, a 15x8 with 4.5" BS will center the wheel in the back and allow at 275/60R15 tire no problem. :)
     

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