Tire printed with 6 perimeters is as suspected MUCH stiffer, and seems more than capable of supporting the weight required. The center weight supporting section is basically solid now while the outside still has some open areas. Honestly, I suspect no infill is required at all with 6 perimeters.
However, as I also feared it is MUCH more difficult to get it on. And as I suspected getting the tires off is all but impossible, even the much flexier version with only 3 perimeters. I ended up having to cut it off.
Testing one more tire idea where I added a bit of a fillet to the outer edges – more for looks than anything since nothing really rides on that surface…but it will give them a more rounded profile if it prints ok…just may push the angle a bit far past what can be done without support…but we’ll see.
Whichever comes out better I’ll print 3 more of then dig in on printing up some hubs. Also going to make a quick trip to HD to pickup some 1/4″ MDF so I can cut at least one Y plate and a few bolts/nuts so I can test-assemble one and see how it rolls on my table 😀