The one pic looks odd with the grab bar but with angle u cant realy see than i saw ur post about cutting the grab bar soi looked again. The grab bar goes on the outsides of those flat spots, to the right of the round frame tubes not inside the slot and thats because right insire the slot is a welded nut, looks like ur bar is after the welded nut leaving nothing to tighten making it kind of just float. Is ur grab bar tight? I can snap pics of mine after work to show if you want.
But wowww this looks good, been looking at doing one but i have a few years before my daughter moves up this big. Loveee the kart wheel looks. Hey when stancing cars and putting 195/55/15 tires on 9.5 inch wide rims (2 tires side by side would fit as if a dually but ur making one stretch to fit) banners dont work eitger, the onlyyyyyy way is spraying eather, shot of air hose, and a tourch, they pop the bead right on, i gaurunteee u the kart tires will. A kart tire is the size of the rim just a stiff bead to seat, if a car tire can stretch farther than a 45degree u should get it first shot