SIDECAR77 wrote:Sorry, its a 66 cb77 superhawk
No apology necessary. Don't do it again!
I'd hazard a guess that the cams are out of sync -- i.e. one shoe's leading end is braking whilst the other is barely making contact with the drum. There's obviously a set procedure, but I got mine just right thus:
- Drop the back wheel out; clean the brake dust away with a proprietary brake cleaner (wear a dust mask) and inspect the friction material for excessive wear (2.5mm is the low limit)
Remove the clevis pins on the both ends of the linkage between the cam levers
Remove and lube the cam spigots, bushes & cams using copper grease, best done with a ½" paint brush; reassemble the brake plate & hub
Reinstall the wheel (leave the cable and the linkage off for now)
Operate the main lever (from the cable attachment hoop end) to full travel and observe the angle against an imaginary centreline running through the axle and the cam spigots -- minimum angle at the "pull" side should not be less than 100º at maximum travel of the lever; if the angle is anything like approaching 90º, move the lever c/w a spline or two
Operate the main lever by gripping the shorter end using a vise-grip -- several wraps of duct tape around each jaw will protect the lever / chrome -- until it makes good, firm contact with the drum; mark the cam spigot boss (where the spline exits the brake plate) and the lever with a pencil to set the travel datum
Carry out the same operation with the slave lever
Re-attach the linkage and observe the pencil marks' alignment; adjust the length of the linkage rod until the pencil marks are aligned -- the main and slave levers should be as near parallel as possible. If they aren't, re-spline the slave lever to match the main lever at the point of the brake shoes' friction material's contact with the drum. If this is necessary, then re-mark the slave lever's travel, starting over from the red text.
G'luck!
