That tire machine was a real good investment for me.
It works great on steelies and rallye wheels.
Saves me $10-$20 a pop to do roller wheels and even the tires on my Satellite.
I paid $75 from a scrap yard, and it paid for it's self in about 3 months.
I was able to mount a 255/55/17 on my Dakota R/T 9" rim
once by having the rim upside down, but was not able to dismount it.
If the screw post was taller, it could do 7" and wider wheels.
I've thought about welding an internal threaded extension on the bottom of the cone, but the "coats" one I bought from ebay has a different thread pitch
One of these days, I'll open it up and see if the post can be raised from the bottom side.