I was out doing some measurements with my current tire and rim, what I have on order, and the stock carrier.
I think the Retrofit Off Road rear tire mount would have to be cut down to 6"-6.5" to fit right with what I have and am thinking, maybe shorter, and could probably be made adjustable for rim back spacing, I just dont have the skills, I dont have it yet so we will have to get it to fit it right and weld up to some angle iron and a lower plate to clamp to the rear seat mounts. This is all to make a JK or JKU inside tire mount, this may only work with the JK. I need to look at a JKU with the rear see removed.
Im kind of going nuts waiting for my neighbor to get back and look at this project for a proof of concept. I do think a strap over the tire would be a good idea even though Scherb's design looks dang strong, I think some O-ring bolts can be added to the clamps to the rear seat mounts easily, as I dont run a rear seat.
With a stock, or narrower tire then I have, this would give 17-20" between the tires if you mount two inside, maybe more or less room. Ild have to remeasure for a single spare, stock or what Im running. I think with my tires Ill have about 14" between the tires if I have two back there, it's still enough room for my dog as everything else goes on the back rack or in the trailer.
XJs and ZJs, Ive had both, have always come stock with a spare inside the cabin so I dont see why there wouldnt be a market for this in a JK or JKU Again this may only work with a JK. With the Retrofit Off Road Tire covers I dont see a problem with the idea of having a spare in the cab.
Yes I'm kind of obsessing on this idea. I just need the parts I have on order and my neighbor.