| Change the belt when it shows signs of wear or cracking. Don't wait until it's laying on the ground under the bike a 100 miles from nowhere.
As for sprockets look for cracks in the hub and check torque on the bolts per manual instructions. If you don't have a HD manual yet GET ONE - it's your bible to keepin your bike on the road and healthy. The maintaince sch. in the manual will help you plan ahead so you don't have unwanted surprises in the middle of BF nowhere. S**T Happens; but at least you have done everything possible to avoid it that you can. | 
