Gen2/Drive Belt Adjustment

< Gen2
Goal
Align and set belt tension to avoid bad wear and early breakage.
Alignment of the belt is critically tough to get correct, and needs to be done everytime adjusting tension.
Zero's Official Owners Manual has a good procedure from which this is derived. Check that first.
Video instruction
Zero SR: How To Adjust Your Belt on Youtube by NewZeroLand:
Tools
27mm hex socket
Breaker bar
Torque wrench set to 75ft/lbs or 102Nm
13mm open-end wrench
Instructions
  1. Place the motorcycle on a Lift or rear stand so the wheel spins freely.
  2. Loosen the rear axle nut on the right side (27mm) with the breaker bar.
    Rear Axle Nut and right adjustment bolt Rear Axle Spacer and left adjustment bolt
  3. Loosen both left and right belt tension jam nuts (13mm) that face forward inside the adjusting gap.
    Rear Axle Nut and right adjustment bolt - loosened Rear Axle Spacer and left adjustment bolt - loosened
  4. 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.
  5. Check that the belt is aligned with belt tension in the right range.
  6. Re-tighten the left and right jam nuts (13mm).
  7. Tighten the axle nut (27mm) with the torque wrench (to 75ft-lbs).
References
Belt alignment discussion
How to Adjust Your Zero's Belt
Notes via Shadow