X3N belts are hygroscopic and will contract in length due to water retention.
Harley-Davidson drive belts have been made of several different types of composite materials over the years. Belts up until 1999 were made from Aramid fibers, a form of Kevlar. Belts made in 2000 and later used carbon fiber strands, increasing their strength and longevity, but decreasing their twist and flex factors. In 1994 Harley, in conjunction with the Gates Co., formed a special team to create a better, longer lasting belt design. All belts produced in 2000 and after use this new formula. All 2000 models and beyond — except touring models — are now fitted with a 1 1/8″ X3N belt.
1. X3N use carbon fiber cords which are stronger, but more sensitive to twisting and crimping.
Locate the rear cotter pin in the axle bolt and remove it with the needle-nose pliers. Loosen the rear axle nut with the 1-inch socket and socket wrench.
2. The belt should no longer stretch after 2,500 miles, allowing it to stay in adjustment longer.
Turn the axle adjuster nuts — on each side of rear fork — clockwise to increase belt deflection (increase tension), or counterclockwise to increase belt deflection (decrease tension).
3. A belt should be reinstalled in the same direction as it came off.
Turn each adjuster nut exactly the same number of turns in order to maintain alignment of rear wheel.
4. Any cuts, tears or fraying near the edge of the belt could compromise its integrity, causing a safety hazard.
Check rear wheel alignment. the wheel must be centered — zero lateral offset — between rear fork tubes, and wheel axle must be perpendicular to rear fork tubes.
5. Like a drive chain, reversing belt direction can cause premature wear.
Belt tension should be 9/16 inch to 11/16 inch when measured with the Belt Tension Gauge. Tighten the axle nut to 60 to 65 foot-pounds of torque with a torque wrench. Install the cotter pin.