Don't neglect engine V-belts. These simple items rotate thousands of times each time you take your 900 series out for a drive. Check periodically for visible cracks and glazing of the V surfaces. You don't want to have a belt break at an inopportune time.
Some applications have more variances than others. Many V-belts have the size marked on the outside edge of the belt. Depending on age and driving conditions, you may be able to still read them. (A couple of clicks on the starter will normally rotate the belt around so you can check the circumference of the belt).
