YAMAHA CHOPPER PROJECT
DESIGN | MAIN | ASSEMBLY

2006/05/07:
The only real "moving parts" I need to build are the foot controls. Foot levers need to move the gearshift lever on one side, and push the brake master cylinder on the other. Enter the linkage puzzle, and its solution:

At first I was thinking I could get away with my own makeshift hinges, using a bushing over a bolt (like I'm doing with the foot control levers). But Sean sent me the Midwest Control site and it became a no-brainer. They have spherical rod ends at a reasonable price (compared to ridiculous catalog prices) meaning I could do things properly, and alignment wouldn't be an issue at all.
The brake master cylinder has a 1/4" receiver for the plunger actuator, so I decided on 1/4" rod for all the linkage. (Although 3/8" seems more standard, less bendy I guess). So 1/4" rod ends were ordered.

So after cutting lengths of rod, the rod needs to thread into the rod end. (The rod ends are 1/4"-28, which is the less common "fine" thread pitch) Just spin a 1/4"-28 die down the rod:

And then drill and tap a 1/4"-28 hole in the lever arm to screw in the other end:

And now I have a pushrod to activate the brake:

Note that the foot control lever isn't done, I wanted to line up the linkage before shaping the bottom arm of the lever. Also note that a brakelight switch needs to be added to the system, as well as a stop to prevent pulling up on the brake lever and yanking the pushrod out of its home.

And then on the other side of the bike, I took the gearshift lever, chopped off the foot/toe pad, turned it around so it curves under the engine and out of the way, and drilled and tapped a 1/4" hole in it.


DESIGN | MAIN | ASSEMBLY
email: mikebike@rocketcar.net