Just got my $10 Trek 560 find back together enough for a test ride. The middle 2-3 gears jump VERY badly. Could this be an adjustment thing? I'm thinking the cogs are done, because the PH-10 wheel I swapped in exhibited none of the problems. The weird part is none of the teeth are any more worn than the others. I can pedal normally, but any kind of load makes it pop and slip. Sheesh! Guess I can rob the one off the P8, it's already missing the pedals and seat anyway, lol.,,,,BD