With a quantity of two pieces, the Bearing(25x33x30) is the most used part in the REAR SWINGING ARM (MODEL L) diagram.
The most reasonably priced component used on the Gsxr750 1989 (k) (e01 E02 E15 E16 E17 E18 E21 22 24 25 34 39 53) Rear Swinging Arm (model L) is the Bolt 6x20,with Plain Washer.
Some items from this specific schematic: Washer, Bearing(25x33x30), Spacer,rr Torque Link Rr, Washer.