toe in question

[offroadrolls]

Where is toe in measured from? If the spec says "1/8" toe in" is it supposed to be measure from the rim or the tread of the tire? I would think an 1/8" at the rim would naturally be more at the tread of the tire and visa versa.[S[S

 

[Old Iron]

The alignment shops use to use the rim, If they still do.
I made a toe bar tool out of 3/4"x 3/4" square tubing. It has two 12" vertical pieces and a 6' long horizontal. They are welded together to make a long U shape
I put one side against the rear side of a tire and measure the other then, move the tool to the front side of the same tire and measure the other side.
This measurement will be 1/8" more than the rear to get 1/8" toe.

 

[donsrods]

Yep, I just run a tape measure at the very back of the tire and then set the front to be between 1/16th and 1/8th of an inch less. That gives a pretty close toe in for a straight axled car. I measure the actual rubber of the tire, not the wheel, and I pick a tread to use as my measuring spot.

 

[bob w]

ditto, donsrods

 

[MercuryMac]

I also use the tire tread to measure from.

 

[smallfoot]

Tread measured here too...

 

[Old Iron]

Tread would be the easiest.
I made the tool when I was asphalt circle trackin. The slicks didn't have tread