Vesconite side bearer guides for Constant-Contact Side-Bearers (CCSB) help reduce bogie rotational resistance while damping hunting. CCSBs have a larger effect on bogie rotational resistance when a wagon is unloaded. The result is potentially higher angle-of-attack between wheel and rail if the friction at the CCSB interface is not carefully controlled. 

vesconite_side_bearer_liner_y25_bogie