Dremel belt sander tracking

[J. Hoffman]

So I thought I got a pretty good deal on a little Dremel 1731 Belt/disc sander. I picked it up for $30 and figured it would work ok for some handle sanding or even sharpening. Its a bench top 1x30 belt sander. The belt that was on it was very old and tracked well on the wheels. It was however formed to the convex of the wheels. I replaced the belt and can't get it to track at all. The knob on the rear wheel doesn't seem to adjust the tracking at all. Does anyone have any suggestions for this little belt sander?
Thanks in advance.