Originally Posted by chevrunner21

Originally Posted by eb110americana

I don't know about the safety bead, but if it's a matter of not mounting tires because it simply isn't possible (rather than a safety precaution due to a lack of a safety bead), then it's the drop center. The drop center is labeled as "Well" in the thumbnail above my post. I've worked for a couple of major tire shops, so I know what I'm talking about. This drop center allows the bead to have slack in it while you mount the tire so that it can stretch around the rim flange. The lower profile the tires, the more important the drop center becomes, and the more difficult mounting is in general.

The problem with these wheels is likely that the drop center is too far from the outer rim flange to mount a tire. Generally the drop center will be a couple of inches from the rim flange at most. Some wheels are "reverse mount," where the drop center is closest to the inner rim flange and the wheels are placed face down on the tire machine for mounting/unmounting. I would think that this type of wheel, though much less common, could be widened from the outside for extra deep dish without issue. Alternately, if the wheels were already deep dish and the drop center was outboard of the spokes, and if the wheels were widened AT the drop center (effectively creating a wider drop center valley) that should work too. Unfortunately for the OP and his amazing work (the JB Weld hero), these are more traditional wheels with the drop center towards the outer edge.