How to Measure Rims

[70GTZ28]

OK, how do I measure my rims? I have TT II, that are suppose to be 17X9.5. When I was at the tire shop getting my M/T 295/45/17's mounted, I had the tech measure the rims (it looked like a Forecep type of tool). The rim measured out 10 inches instead of 9.5. I noticed that he didn't measure the outer edge of the rim. He placed it on the area where the tire would make contact. Please help, I'm so confused now.

[kmcanally]

If it is actually a 9.5" wheel the overall outside width should be approx 10.5"

[Rubes]

The width measurement is taken from bead seat to bead seat, on the iside of the rim where the tire actually contacts it. The back spacing though, is measured to the actual outside edge of the lip.

[MonzaRacer]

anmd where the guy at the tire store measured is where the machine wants measured as this is where the weights go.
Now if you find one of the tire stores with a Hunter DSP tire balancer they can actually measure it on the inside and it has software that allows the use of tape weights AND they can hide them behind the spokes and such.
At the Firestone I worked at we had one and it was awesome, it would even balance bent wheels. Another neat trick was you could at the touch of a button on tough to balance wheels(bent,wierd offsets) split the weights so they would sit at a 10 and 2 positiion instead of at a 12 oclock type placement. I would use this on wheels that were going on performance cars.

[Boesch]

The width measurement is taken from bead seat to bead seat, on the iside of the rim where the tire actually contacts it. The back spacing though, is measured to the actual outside edge of the lip.

That's exactly right. Take a look at this web page and it should answer all of your questions on measurements.

https://rsracing.com/tech-wheel.html

Dustin