just lost my tire pull virginity :)

When I went to my 4th set of PZero Corsa tires on the 2008 SL

a few days ago, I lost my tire pull virginity. Yep, that's right, my

first time! As it turns out, one of the two front tires did turn out

to be bad: minutely misaligned outer bead, and a seemingly more

soft side wall on one side, resulting in conicity, which in turn did

cause my car to pull left.

 

During my first drive I noticed that the silver stripe at the CF top

of my steering wheel suddenly pointed right... even though I was

going straight, and that the pull to the left was especially strong

under heavy "kick it" acceleration.

 

An initial visual inspection only suggested that the gap between

the top of the tire and the bottom of the fender seemed ever so

slightly smaller on the front left than on the front right. It looked

as if someone had lowered the left side by almost 1/2".

 

So... back to shop I went. Now, while the front wheels could be

moved to the rear (to see if the pull disappears) the back wheels

don't fit on the front (since they are wider). So we started with

a different experiment: a different set of wheels + tires. No pull.

So the suspension and alignment (i.e. the car) probably were not

the culprit. Next we swapped the two front tires. We could have

tried a simple left-vs-right swap, i.e. running them backwards for

a very short test drive, but that still wouldn't have told us which

one to blame. So instead we swapped with a full unmount/mount,

in the course of which we already started to suspect what used

to be the front left, and now became the front right -- that tire

just didn't look and feel right. And sure enough, once mounted on

the right, at least the lowered suspension Ghetto look was gone.

The car still pulled left of course, but I could begin to tell that it

was now coming from the front right side.

 

One day later... a replacement tire from TireRack was delivered,

went on the right front wheel, and voila, all is well again!

 

Now all that's left is for UPS to pick up the bad one, for return to

TireRack. So far I'm very pleased with how painless this has been

in terms of process: a phone call, describing the problem, and the

replacement was on its way.

 

http://www.tirerack.com/tires/tiretech/tec...e.jsp?techid=12

 

Oh and no, the difference in circumference (left vs right side wall)

is too small to show up with my simple "piece of string" method. It

really only shows under load i.e. when on the car.

 

So, why did the shop not notice this during the test drive after the

initial installation? Because they were taking it easy: it was pouring

heavily during that week. (Insert bad memories of gvan going for an

alignment, and suffering from a bad "test drive" in the rain, followed

by many weeks without a car.)

 

Anyway.

 

So now I know how tire pull feels. :-)

 

I probably wouldn't have noticed it, had it happened on some cheap

car with shitty suspension and less-than-perfect alignment. :-o

 

Drive safely!

good lesson for you...