Ok, they're supposed to rotat, but not that way

September 2, 2009 5:50 PM

If a car is hit in a collision and is sent into two 360 spins (not rollovers), obviously an alignment needs to be done (in addition to all other repair work), but my question is: Are the tires safe to drive on?

Long story short:

"car 1" is traveling at 55mph on highway
"car 2" Illegally enters highway and collides with "car 1"
"car 1" is sent into two 360 degree spins and comes to a halt 100 feet down the highway. Laying on the brakes the whole time.

The question is:

Does the action of dragging the tires a way they aren't usually meant to rotate for this period adversely effect the future safety and/or durability of the tires.

Tires are relatively newWrangler SE with 85%-90% tread life remaining.

Thanks in advance!

posted by sandra_s to Travel & Transportation (14 answers total)

No. They've been flat-spotted. Replace them.
posted by Zambrano at 5:57 PM on September 2, 2009

They're safe, they just might be a little out of round. If the car's still in driving condition, take it for a spin and see if the vibration is too much for you. They'll never be perfectly round again, but they aren't going to explode if you use them.
posted by hwyengr at 6:01 PM on September 2, 2009

That could only be determined for certain by examining them.
posted by Chocolate Pickle at 6:01 PM on September 2, 2009

Impossible to know without looking at the tires. Get your mechanic to inspect them.
posted by orme at 6:03 PM on September 2, 2009 [1 favorite]

Likely OK. If the wheels were rotating even slightly as it spun (momentum, or the foot coming off the brake on impact) the wear will have been distributed. But I'd check for any obvious flat spot just in case the wheels were locked all the way through the spin.
posted by Hardcore Poser at 6:25 PM on September 2, 2009

Even if they have a little flat spot, with 80-90% tread, they'll wear almost normally for the remainder of their life.
I've had customers neglect their tire rotation maintenance and I've performed a tire rotation after they developed some tread irregularities. A visit or two later, the tread was starting go wear normally again and negate some of the wear pattern.
I wouldn't worry too much about it. The alignment is the critical concern.

Also, if your car has ABS, some flat spotting will have been mitigated. The reason that the brakes pulse during ABS application is to constantly refresh and rotate the tire contact patch, preventing the heat-friction and surface degradation that would result in flat-spotting.
posted by Jon-o at 6:58 PM on September 2, 2009

I did a couple sliding 360s in my high school car (racing, on a street that has a dip, a bend, and rough patches all at the same place) and didn't have a problem.
posted by notsnot at 7:48 PM on September 2, 2009

As described it sounds like about the equivalent of a couple skidding stops of wear. It's pretty unlikely anything but very minor damage has been done to the tires. Check with a tire place but it seems pretty unlikely to have done any real damage beyond a couple flat spots.
posted by Mitheral at 9:00 PM on September 2, 2009

Inspect the tire. Use something (a notched match perhaps) to act as a depth gauge, to check that the depth of your tread is consistent around the tire. Don't forget to roll the car forward to check the section that's on the ground.

Have this information in your mind when you consult with whoever is doing your re-alignment, as they will likely have a view.
posted by jjderooy at 9:09 PM on September 2, 2009

A couple of years ago, while on the highway, I had to go from 60 to zero in what seemed like the shortest of forevers. Immediately afterward, it was like driving on a very very bumpy road. Feeling them go in and out of sync was kind of neat for a few days but I replaced both front tires that weekend. I figured the extra vibration would create enough other kinds of wear that it could damage something else down the road.
posted by wobh at 9:27 PM on September 2, 2009

Their insurance should be paying for all of this anyway, get the tires.
posted by rhizome at 11:42 PM on September 2, 2009

Too many variables to say for certain unless inspected by a trained professional. Have a good tire place inspect them. At the very least, they probably need to be balanced again. Seconding rhizome, their insurance should be paying for any damage that was caused by the accident, which may include new tires.
posted by Taurid at 12:17 AM on September 3, 2009

Their insurance should replace, however;

Wouldnt have thought the skidding would have caused significant problems. (If you slid into something then further damage would be expected). The skid alone might have caused a minor flat spot which will soon disappear. If the steeling wheel vibrates or shakes then you may have a problem.

Check for damage to the sidewalls though. It's possible that something like this would have disrupted the structure of the tyre. Have a careful look for lumps bulging out of the tyre or for chunks torn out of the sidewall. Either of these make the tyre very unsafe.
posted by BadMiker at 6:13 AM on September 3, 2009

I would have a tire shop inspect them on their balance machine.
posted by luckypozzo at 6:30 AM on September 3, 2009