STRUCTURE OF PIVOT PART FOR REAR SWING ARM

摘要

PROBLEM TO BE SOLVED: To prevent deformation of pivot plates even made of an aluminum alloy when a pivot shaft is installed by clamping. SOLUTION: A pivot frame cast in an aluminum alloy has a generally forward-opened U shape having a left wall 40 and a right wall 50, between which mounting bosses 70L and 70R on a crankcase 13 are interposed as well as outside which bearing parts 74L and 74R on a rear swing arm 14 are set coaxially so as to be fastened en bloc via a pivot bolt 77 driven in from one side against a nut 78 on the other. Between the right mounting boss 70R and the right wall 50, an adjusting collar 75 is interposed with its immovable portion 81 fixed to the right wall 50 and its movable portion 80 kept turnable by a special tool to hold the clamping torque of the nut 78 constant.