Hi Kim,
The O.D. on my zip-ty tire changing stand is 16 3/4 inches.
It is similar to the one above without the lever. I use my knees and don't see the need for the lever, I can see that it would be good for breaking the bead on atv tires though...
A link to the zip-ty unit is here...
http://www.ziptyracing.com/products/...px?id=MTMwOQ==
jeff