The ID if the tire is 70mm, but the OD of the 6 shooters is 76mm so there is a lot of stretch in the airless tires. I would suggest an OD of 80mm to reduce the slippage and make a tight fit.
Don’t forget you’ll probably need to provide wheel spacers of proper lengths for installation if you sell these as your pics don’t look to have any spacers installed with the bearings in…
No spacers = big no no, you need inner race support.
I would thicken up the beads on those too. These tires can inflate to some pretty high psi.
I popped the side of a plastic hub off riding in the riverbed when I first started testing 6" tires.
3.5" x 12" solid round acetal stock to be sliced into 1" thick puck
Hub can be customized to fit mountainboard 12x28x8mm bearing (MBS and Trampa), 9.525x22.225x7mm (Trampa Street Carver), or standard 8x22x7mm (TB218, Evolve, …)
I need two sets of wheel gears for mbs rockstars. PM me if you think this task is good for you. I’ve seen POM, nylon with carbon fiber, and aluminum. Trying to make a decision here