Model: "Mag"

OK, I'm pretty sure I assembled this thing properly. But when I seat rear tire onto chrome roller and rotate the trainer's q-release lever it misses the bike's lever by 1/2 inch or so (i.e. it's off-center). I have tried rotating the tension knob, which does not seem to make a difference, and if I turned too far it might fall off the l-screw.

Any ideas???