Primo belt drives are developed and manufactured by Harley riders for Harley riders. Before the first Primo belt drive was sold, the belt drive systems had been tested on a Top Fuel drag bike until they would stand up to the strain. Each kit consists of the complete belt drive unit, a sprocket shaft nut, all necessary hardware and detailed installation instructions.

Early model belt drives featuring the ultra severe-duty 11mm Aramid Polychain belt. These belt drives are designed for enclosed primary fitment, either within aluminum primaries or within tin (stamped steel) covers. For the later aluminum primary models (1965-1984) two kits are offered for kickstart and electric start models. The earlier tin primary models are available for tapered (1937-1954) or splined shaft (1955-1964) applications, kickstart only.