Rear brake question

[Roberd42]

My rear brake is a mess. This is my first bike with drums so I'm not real familiar, other than some old beetle drums I rebuilt one time. These are mechanical and spread on a cam it looks like from parts drawings. I haven't taken it apart yet, I'm hoping it's something stupid I'm doing wrong. The PO broke the brake push rod at the thread. He put on another and it was bent in the thread.

With the pedal at rest the brakes are on. When you press the pedal the brakes come off. If you press far enough you come to a tight spot, something pops, and the pedal come way up high and the brakes seem to work correctly. But the pedal is way high up at rest. All this movement is what bends the rod and has bent the stop switch spring. I've tried moving the arm on the splines in different positions. I've tried putting the arm under load, then the pedal goes way up again. I'm starting to feel stupid. My next step is to take it apart and reverse engineer the thing to find the problem. Maybe something is installed backward internally, if that's even possible?

[Sam Green]

My rear brake is a mess. This is my first bike with drums so I'm not real familiar, other than some old beetle drums I rebuilt one time. These are mechanical and spread on a cam it looks like from parts drawings. I haven't taken it apart yet, I'm hoping it's something stupid I'm doing wrong. The PO broke the brake push rod at the thread. He put on another and it was bent in the thread.

With the pedal at rest the brakes are on. When you press the pedal the brakes come off. If you press far enough you come to a tight spot, something pops, and the pedal come way up high and the brakes seem to work correctly. But the pedal is way high up at rest. All this movement is what bends the rod and has bent the stop switch spring. I've tried moving the arm on the splines in different positions. I've tried putting the arm under load, then the pedal goes way up again. I'm starting to feel stupid. My next step is to take it apart and reverse engineer the thing to find the problem. Maybe something is installed backward internally, if that's even possible?

Perhaps you haven't got the correct foot peddle and rod. Pictures of your set up would help. Drum brakes are so simple but when you bring POs into the equation, anything can go wrong.

Sam.:)

[VegeKev]

Sounds like your brake rod is too short.
Mine is 470mm long.
Hope this helps
Kev.:)

[Roberd42]

Mine is 490mm from the adjust end to the pin. I get full travel of the arm, just no braking until I pull the arm to where it would bend the rod. If I move it up on the splines it will brake correctly but arm pressure in the hub pulls back on the pedal so that it is extremely high up. This is in the configuration where there is no brake through full movement of the pedal. You can see wit just a little movement the pedal bends the switch spring. I'm wondering now if I have the correct pedal. The pedal connector has a pin going through it with a cotter key. Looks correct per the diagrams. I'll post some pictures in another post from my desktop.

[Roberd42]

Photos

[ByTheLake]

The passenger foot peg should flex up and down, not left and right :-)

[Spokes]

You have the wrong brake pedal. The stop light spring does not bend around the swing arm post. It is likely the brake rod is wrong as well. I would double check the brake shoes and mechanism in the rear hub as well.

[Roberd42]

Will do. I was afraid of that. Let me get to finding the right parts. :/

[Roberd42]

Well it looks like my pedal and Rod are the same as those listed on eBay. I don't see any difference in what I have. The spring isn't binding on the swing arm pivot. It binds against the brake pedal itself where the Rod connects. I was depressing the pedal slightly in the photo to demonstrate where it was binding (probably should have said that). I'll take the hub apart and see what's going on in there.

[Roberd42]

Turns out my pads were almost gone causing too much travel for the pedal. I'm going to order some new Bangkok ones and try those. Also my drum looks thin but I don't have a way to measure a diameter that large to check the book spec. How does this one compare to yours?