[djnolan]

Use an automotive stethoscope to listen to the WP bearing and the roller bearings. It is a pretty fine line between too loose and too tight. You have to try a couple of different tensions, but when it is too tight it is pretty obviously a very shrill whine (and wears out the bearing) , and when too loose the belt flops.

Yours may be too tight judging by the amount of force needed to spin the WP pulley.