I recently had to R/R the rear wheel on my '05 FXSTD. After completing the installation, adjusting belt, etc., for no particular reason, decided to jack up the rear wheel and watch it rotate while on the lift; just curious.
A link to a video (file is too big to attach) shows the wheel rotating in second gear. Watch the belt jump up and down but stabilize when the clutch is disengaged with about 13 seconds left and start jumping up and down a few seconds later when the clutch is engaged. There is an intermittent mechanical noise associated with the belt movement but it is hard to hear over the exhaust. I don't know if this is normal but it almost seems as if something is interfering with the belt rotation and/or the rotation of the drive pulley.
However, when I ride the bike, there is no noise, the Baker DD6 shifts flawlessly, there is no vibration; everything is flawless. So, if there is something wrong, it does not present with the tire on the ground under throttle.
Take a look at the video;just looking for an input from the forum on whether I should be concerned or not.
https://youtu.be/7PaABMGVYkI
Nothing to be concerned about. The "jumping" is caused by total slack in the driveline & the "shock" of the cylinders firing. Rub a 2 x 4 against the tire & I bet it quits jumping.
load vs no load- common to see.
Thanks guys for confirming. I was pretty sure the action had to be normal and the result of the load vs no load. The question I should have asked in my OP was what causes it. I never thought about the impact of the shock imposed by cylinder firing in a no load situation; makes perfect sense and I should have thought about that before posting. :doh:
Watch some motorcycle racing and when they show closeups you will see their chains whipping all over the place. 100% normal. Just like serpentine belts on cars, even with tensioners on them they still bounce around.