From Unofficial Zero Manual
The official manual has a good procedure from which this is derived. Check that first.
Alignment of the belt is critically tough to get correct, and needs to be done everytime adjusting tension.
- Video instruction
- Zero SR: How To Adjust Your Belt on Youtube by NewZeroLand:
- 27mm hex socket
- Breaker bar
- Torque wrench set to 75ft/lbs or 102Nm
- 13mm open-end wrench
- Place the motorcycle on a lift or rear stand so the wheel spins freely.
- Loosen the rear axle nut on the right side (27mm) with the breaker bar.
- Loosen both left and right belt tension jam nuts (13mm) that face forward inside the adjusting gap.
- Turn both left and right adjustment nuts (13mm) one quarter turn at a time to the desired belt tension.
- Ensure that the alignment marks on either side of the swingarm indicate that the wheel and belt are aligned.
- Roll the wheel forward and track it flush with inside of rear sprocket.
- For proper alignment, the belt will track exactly centered on the wheel sprocket with a 1mm gap to either side of the belt relative to the sprocket.
- Once tension is set and tracking is flush to the inside, tightening the axle nut to 75ft-lbs will tend to nudge belt approximately 1mm to the outside.
- Measure tension by rolling the wheel forward while plucking bottom side of belt or using tension gauge over several revolutions.
- Expect tension to vary slightly as wheel is rotated because front and rear sprockets are only round to a certain design tolerance.
- Check that the belt is aligned with belt tension in the right range.
- Re-tighten the left and right jam nuts (13mm).
- Tighten the axle nut (27mm) with the torque wrench (to 75ft-lbs).