Interesting tire observation

SuperDave

Since switching to disc brakes, I have been very critical of how the car is driving. '''Like feeling and hearing everything. I noticed that I had a small "drift" to the right. not really a pull, and not related to braking. Just a gentle drift to the right. In the process of trying to clear up the wheel rubbing the caliper stuff, I switched left to right and right to left..The drift went away! So I got out my tire tape from the old circle track days and checked the circumference of the tires. (We used tire "stagger" to help transfer diagonal weight and to help the car accelerate of the corner.. IE. A larger right rear than left rear. ) all are the same brand, size, lot number etc. Same pressure. One front tire measured 87 1/4" the other measured 87 3/4". With the larger one on the left front I lost my r/h drift. I checked the rear ones and found one was 87 3/4". the other 87".

These are bias ply tires. My caster spread was less than 1/4degree. Before I could finish all my measurements, I dropped my Longacre caster camber gauge and broke it.. Dang...So...If you have a pronblem with either a right or left pull, check your tire circumference. They can vary quite a bit.

Davew

[Deleted User]

this is very interesting. i've wondered for years when you have the front end aligned and it pulls a little bit one way or the other, the first suggestion is to switch the front tires from one side to the other. . . great trick. both my daily drivers are pulling a little bit, i will measure them all this weekend and figure out which one to put where. thanks for the excellent explaination.

davidh (never too old to learn something new)

hornet53

I thought you weren't supposed to switch bias ply side to side. Or was that radials?

Uncle Josh

Old wives tale. My Sienna with full size spare recommends a corner switch as part of the rotation.

[Deleted User]

i've been told since radials came out: back to front, front to opposite corners of rear. takes quite a few roatations before everyone ends up back where they started. . .

Park_W

David, that rotation pattern is right for a rear wheel drive, but for front wheel drive you move from front straight back, and cross the rears as they come to the front. The idea is to swap sides with the tires that haven't been on the "drive axles," while those that have been "driving" stay on the same side.