Kevin,

If your metal cutting saw is like many I've seen it may be due to the
guides on the horizontal metal cutting saw forcing the blade to twist
at an angle. With the guides forcing the blade to twist, maybe a
crown is not enough and the wheels need the lip on the back to keep
the blade tracking properly.

I've been working on designing a horizontal woodcutting bandmill and
I've found that there are all kinds of tires, crowned and uncrowned,
and solid steel wheels (no rubber tires). So, it seems almost like a
Ford vs Chevy issue. The large industrial saws seem to use crowned
solid steel wheels, many of the smaller bandmills just use v-belt
sheaves with a belt slipped over them for bandwheels.

I've seen a few internet discussions and papers on bandwheel crowns
and I guess the physics of it can be pretty interesting.

Bob