Checking Deflection
See
Figure 1. Check belt deflection at the loosest spot in the belt with the transmission in neutral and the motorcycle at ambient temperature. Use the
BELT TENSION GAUGE (Part Number:HD-35381) to apply 10 lbs. (4.5 kg) of force at the midpoint of the bottom belt strand with motorcycle resting on jiffy stand.
See
Figure 2. Locate the belt deflection window on the rear drive belt guard/debris deflector and note the belt position relative to the deflection graduations.
Belt deflection should be within 5/16-3/8 in. (7.9-9.5 mm). If belt tension adjustment is necessary, see a Harley-Davidson dealer or follow the instructions given in the applicable Service Manual.

WARNING
Be sure wheel and brake caliper are aligned. Riding with a misaligned wheel or brake caliper can cause the brake disc to bind and lead to loss of control, which could result in death or serious injury. (00050a)
Check rear brake caliper position on rear brake disc. Disc should run true within brake caliper.
Figure 1. Belt Deflection: FXDSE
Figure 2. Belt Deflection Window