Not normal. Check your trans/belt sprocket on the right side (under the back 1/2 section of the right side case)and see if the nut is loose and/or wobbling. You will need a special tool to lock the sprocket when you torque it. Something is causing your belt to be too tight, too loose,off center in the sprocket, binding, etc. You should get a service manual for this troubleshoot/repair if you do it yourself.BTW, askwhoever serviced your bike if they adjusted the belt. They may have just tightened it too much. Don't tell them it broke before you ask them...
Note:
All belts, used or new, must never be[align=left]formed into a loop smaller than 5.0 in. (127 mm), and[/align][align=left]must never be bent backwards into a loop smaller than[/align][align=left]10 in. (254 mm). Sharp bending can weaken the belt.[/align][align=left]Used belts must be reinstalled so they rotate in the same[/align]direction as they originally did.
Do not rely on “feel” for the proper deflection as this typically
results in belts which are under tensioned. Always
use H-D BELT TENSION GAUGE (Part No. HD-35381)
to determine the 10 lb. (4.5 Kg) deflection force. Loose
belts will fail due to “ratcheting” (jumping a tooth) with
resultant tensile cord crimping and breakage.
●
See Figure 1-42. Tool must be at a 90 degree angle to
belt both front-to-back and side-to-side in order to obtain
an accurate reading
Secondary Belt SNAPPED
06 FXDLI 
