Help me read this alignment
Drifting
Joined: Oct 2011
Posts: 1,872
Likes: 333
From: Olmsted Falls Ohio
St. Jude Donor '12 thru '24
The alignment I just had done on the C6 was a 'touchless' alignment, where the reflector apparatus attached to the tire and did not touch the rim. Don't know if new or worn tires would make a difference here as the attachment was a small fraction of an inch off the rims. I had never seen this before - kind of a neat setup and still accurate once I figured out how it worked.
Race Director
Joined: Mar 2005
Posts: 10,399
Likes: 25
From: Austin Texas
When measuring in inches the farther out from the centerline the greater the distance. Degree measurements won't change. Form a V with your fingers. The distance between your first knuckle is less than between the finger tips even though the degree is the same.
If the old tires are worn to the inside they do not sit the same as new tires. They are worn with built-in camber on the face of the tread. The inside edge could have 7-11/32" less tread than new. I imagine it is worse with stiff sidewalls vs. old bias tires.
But, I could be wrong.
--Dan
If the old tires are worn to the inside they do not sit the same as new tires. They are worn with built-in camber on the face of the tread. The inside edge could have 7-11/32" less tread than new. I imagine it is worse with stiff sidewalls vs. old bias tires.
But, I could be wrong.
--Dan
The tires flex, they have 800+ pounds of weight on each them. The wheels do not flex. The wheel determines the alignment, the tire just follows since it's flexible and the wheel is rigid.
I do think that alignment should be done with the new tires since anything could change between removing the old tire and installing the new. Do the alignment after the new tires are mounted.
Last edited by haljensen; Sep 29, 2013 at 06:39 PM.
Team Owner
Joined: Sep 2000
Posts: 24,992
Likes: 2,694
From: Far NW 'burbs of Chicago
St. Jude Donor '13
When new tires are installed, the car is lifted or jacked up and the wheels (one at a time or all four at once, should make no difference) are hanging for a little while. I've noticed that the car does not settle down to its normal height immediately when taken off the jacks, it needs to be drive at least across the shop and maybe more- after raising our ride height via the spring bolts, it took a couple of hundred miles for the car to settle to it's new height.
Based on that, I've always had the tech drive the car onto the alignment rack and do that part of the job, before anything that might involve lifting the car off its wheels.
Once, the tech set one of the alignment values incorrectly and I didn't notice it at the time. I drove away and had new tires installed a couple of days later, then realized the alignment error and took it back to be corrected. The alignment numbers had not changed after having the new tires installed.
OTOH,
I don't understand all I know about this stuff.
Based on that, I've always had the tech drive the car onto the alignment rack and do that part of the job, before anything that might involve lifting the car off its wheels.
Once, the tech set one of the alignment values incorrectly and I didn't notice it at the time. I drove away and had new tires installed a couple of days later, then realized the alignment error and took it back to be corrected. The alignment numbers had not changed after having the new tires installed.
OTOH,
I don't understand all I know about this stuff.
