I'm not saying bias is better than radial, but bias tires are still in wide use in lots of applications...
Power King brand has this ST7.50-16 trailer tire
http://www.powerkingtires.com/Tires/Trailer/ST%20Bias/308
and this ST235/85R16 tire
http://www.powerkingtires.com/Tires/Trailer/ST%20Radial/318
that seem to be comparable. The radial is almost 2" wider section and requires a 1/2" wider rim. Is that what you found: too wide to fit?

Try yokohama. I know they did make/sell a 7.00R15 narrow radial and maybe they make a 7.50R16...


Professional Novice