Parts such as the Crank Balancer: Key, Balancer,crank Fr, Nut, Screw are included in the Dr800su 1992 (n) Germany (e22) Crank Balancer parts fiche.
The Screw is the lowest priced item on this Crank Balancer schematic.
The Crank Balancer assembly is constructed from several parts from which the Balancer,crank Fr is the most expensive.