A drive unit for imparting rotation to a drum assembly of a floor grinder. The drive unit includes a rotatable pulley positioned adjacent to and in contact with a rotatable drive surface of a driven pulley of the drum assembly and a drive surface of the drum assembly. The rotatable drive surface of the driven pulley is configured to impart rotation to the rotatable drive pulley during rotation of the rotatable drive surface, and the rotatable drive pulley is configured to impart rotation thereof to the drum assembly.