Cracks forming on the side edge of a rubber belt may be the result of several conditions. Failure to grind a radius on the rubber belt outer edge, as the original radius disappears with repeated surface grinding of the rubber belt, is a common cause of cracks on the outer belt edge. A sharp angle on the belt outer edge causes a focus of mechanical stress which promotes the formation of cracks in this area.

Poor rubber belt tracking adjustment can result in belt edge cracks caused by the excessive force of the belt edge working against the limit roller.

Limit rollers set tight up against both belt edges or rollers set at an improper angle are a leading cause of belt edge cracks. Limit rollers which do not turn due to defective bearings or peeling chrome plating on roller surfaces can lead to belt edge cracking.

Rubber belt edge cracks often are the result of damage to the belt edge by lifting straps etc, during installation of the rubber belt on the shrinking machine.