I run normal tire pressure on the rollers (105-110psi, I'm 180lbs). You'll see the tire compression more I think just because of the angle you're viewing it from. If you want more of a workout without adjusting anything but tire pressure, drop the pressure down to about 95psi and feel the resistance climb.
I have Minoura Mag Rollers and have been very happy with mine. The resistance unit makes some noise every now and then but it provides me with plenty of room to change up the workout.
VW
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