30 miles max... dude, I commuted 4X that distance, AND did another 60 on Saturdays... and I believe you'll find a LOT of folks here ripping up a LOT more miles...
Work on the motor, not the wheels. The returns will be vastly greater.... and cheaper.
Good suggestion on changing gearing... then, learn to up your RPMs and really spin.
When those 10 mile jaunts start to feel like a "warmup," then consider new wheels.