How to Replace a Harley Sportster Drive Belt

Updated April 17, 2017

Harley-Davidson belt drives are highly engineered systems that provide strong, quiet power to the rear wheel from the transmission drive sprocket. Built from super-strong fibres encased in polymer, the belt drive provides low maintenance and corrosion-proof service for thousands of miles. The belt construction eliminates the need for lubrication and frequent tension adjustments due to stretching, unlike the old chain drives.

Lift the back of the bike with the bike jack. Remove the right footpeg mounting bracket. Remove the rear master cylinder and suspend it from a convenient point on the frame with the bungee. Remove the right side transmission cover plate. Remove the brake caliper from the left side of the swing arm and suspend it with a bungee.

Break the torque on the rear axle. Back off the axle adjusters evenly until the drive belt is slack. Remove the rear axle. Roll the tire forward slightly until the belt can be disengaged from the rear drive pulley. Remove the rear wheel from the bike. Remove the belt guard(s) from the swing arm. Remove the bottom shock mounting bolt from the swing arm and swing the shock up and clear of the swing arm. Remove the old belt from the transmission drive pulley.

Install the new belt onto the transmission drive pulley. Replace the lower shock mounting bolt and torque to factory specifications for your year of Sportster. Roll the rear wheel slightly forward of its mounting position and place the belt onto the pulley. Roll the wheel back and replace the wheel spacers and the rear axle. Tighten the axle finger tight.

Compress the rear brake caliper with the C-clamp and place it back onto the swing arm and the brake rotor. Re-install the caliper mounting bolts and torque to factory specifications. Tighten the axle adjusters evenly until most of the slack is removed from the drive belt.

Check the rear axle alignment with the axle alignment tool and align the axle if necessary. Replace the belt guard. Check belt tension with the tension tool. Push the bottom of the belt upwards until 6.8 Kilogram are indicated on the tool. Observe the deflection in the sight window of the belt guard. Refer to factory specifications for your model's belt tension deflection measurement and make corrections with the axle adjusters evenly until the appropriate deflection is attained. Re-check the axle alignment and make any axle corrections with the left-side axle adjuster only. Re-check belt tension once the axle is aligned.

Torque the axle nut to factory specifications. Re-install the transmission pulley cover, rear brake master cylinder and footpeg bracket. Pump up the rear brake with the brake pedal to insure proper feel and to allow the caliper to self-adjust back to its proper position.


Roll the bike with the engine off. Listen for a squeaky or rubbery noise at the belt pulleys. Audible squeaking indicates an out of alignment or insufficient belt deflection condition, and can lead to undue wear and early failure of the belt.

Things You'll Need

  • Standard 3/8 and 1/2 inch socket set
  • 3/8 inch ratchet
  • 1/2 inch ratchet
  • 1/2 inch torque wrench
  • Bike jack (lift)
  • Belt tension tool
  • Rear axle alignment tool
  • Short bungee cord
  • C-clamp
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