One disadvantage of wide rear wheels

m110 · 12-10-2009, 06:41 PM

I have 9" rear wheels with 255 section rear tires on an '88. I had a puncture last night but didn't know it. Entered the freeway and began to notice some vibration...I've got a flat (80mph)! Slowed down to get to an exit (I won't stop on freeways if I can) and smelled some rubber burning and then FWAP! The tire inner sidewall disintegrated.
I've had flats with the narrow stock tires but the clearance with the spring arm is so tight now that it destroyed the tire and even rubbed heavy on the oil lines. Other than the tire everything is Ok (I think). I don't think this would have happened with the large clearance of the stock tires. Just a thought for those with wider tires. Rim looks to be ok.

175K911 · 12-10-2009, 06:56 PM

Are you sure that rubbing is what caused your problem? I run 17x9 Jeff Alton rear wheels with the correct offset, with 255/40 tires and have never had a problem. And that's after 22 track days just this summer. I also have a set of 17x9 Cup 1 wheels with 255's and have lots of room both sides. Both wheels are an et15 offset and have plenty of clearance both inside and out. So much that I'm having my second set of Alton Fuchs made at 9.5" wide.

Without actually seeing the car, I'd guess either the wheels were the wrong offset, or all the marks on the spring plate and oil lines were caused by the tire after it started to come apart. If you've never seen what a tire can do when it starts to separate, check out a NASCAR race as the tire literally destroys the front bodywork and car rip the brake lines apart before the car can come to a stop. My vote is that the tire got damaged and caused the marks.

Is the other side rubbing the alignment bolts or is there sufficient clearance. If it's rubbing too, the wheel offset is wrong. If it's not, the other tire just separated from some other damage.

awdbandito · 12-10-2009, 07:10 PM

I don't think rubbing caused his initial problem. Given the neglible clearance from running larger tires once a tire began to deflate and bulge it began to rub and quickly caused a catostrophic failure. If he had been running a closer to stock tire he would have more wiggle room for a tire to deform.

m110 · 12-10-2009, 07:18 PM

I should have been more clear.
The tires have always fit great--but they are certainly closer to the bolts.
The tire had a puncture and lost pressure. As I slowed down I think it bulged and deformed and then came into contact with the bolts and fell apart. I don't think this would have happened with a wider space back there. I doubt the tire fell apart on its own at speed, it just didn't play out that way but who knows. There is a cut in the inner sidewall that corresponds with one of the bolts. Maybe there was enough speed for the tire to fall apart first, I don't really know.
I did travel through a construction zone on the way onto the freeway--maybe the sidewall was cut.

911pcars · 12-10-2009, 09:17 PM

Quote:

Originally Posted by m110

I should have been more clear.
The tires have always fit great--but they are certainly closer to the bolts.
The tire had a puncture and lost pressure. As I slowed down I think it bulged and deformed and then came into contact with the bolts and fell apart. I don't think this would have happened with a wider space back there. I doubt the tire fell apart on its own at speed, it just didn't play out that way but who knows. There is a cut in the inner sidewall that corresponds with one of the bolts. Maybe there was enough speed for the tire to fall apart first, I don't really know.
I did travel through a construction zone on the way onto the freeway--maybe the sidewall was cut.

Stuff like this happens; hopefully rarely. Here's a thread on a similar incident this past August:

Is this worth complaining to Yokohama?

Sherwood

Bill Verburg · Bill Verburg's Garage

It's for sure tight w/ big wheels and tires

275/40 perfectly centered in a Carrera wheel well leave this gap after the bolts are shortened

eimkeith · 12-11-2009, 02:55 AM

m110, for what it is worth, I had an almost identical failure on my 930 (Right Rear) with stock 9" Fuchs - shredded the tire ALL THE WAY AROUND the sidewall (had to cut the bead to remove it) - and as you may know, there is ample clearance on a stock 930 setup.

Once the tire deflates, the inner rim shell will cut the sidewall due to the camber if you drive onit long enough. I drove on mine probably a minute longer than you did - same burning rubber smell, etc.

Of course, as you say, once the tire comes apart, the flapping rubber acts like a huge weedeater in there. Glad you caught it when you did!