Sheave algnment jig

Discussion in 'Whizzer Motorized Bicycles' started by Traveler, Dec 22, 2009.

  1. Traveler

    Traveler Member

    I seldom get to contribute anything, and this may have been done to death, or look all wet, but here goes:

    I had trouble getting the sheave aligned on my vintage Whizzer. It always had a slight wobble. After thinking about it for a few days, I came up with a simple jig that aligns the sheave from the rear axle. It is simply a piece of wood with a hole drilled in the center to fit the axle. I have it sitting on a workmate bench and resting on another drilled piece of wood. The screws are loosened from the sheave.

    The clamp holds a smaller piece of wood barely touching the inside of the sheave. I slowly rotate the wheel. When the sheave rubs the wood piece with a lot of drag, I use a mallet and tap the sheve in that location from the inside. When the sheave shows space from the piece of wood, I tap it from the outside. When alignment gets real close, I slightly snug up a couple screws and repat, making fine adjustments and tightening screws until the wheel rotates with the sheave just touching the piece of wood as the wheel spins. I tightened all the screws and the sheave is lined up nicely. This will also align a slight out of round sheave.

    The only tools required are a drill, small saw, and a clamp.

    Photo attached.

    Attached Files:

  2. kerf

    kerf Guest

    Aligning that sheave's gotta be a problem and since all the sheaves are the same size, makes me wonder why someone hasn't come up with a cheap plastic system to do it. Yours looks fine, maybe you should refine it and go into business.
  3. Traveler

    Traveler Member

    Here is another configuration I thought about a lot:

    The ideal situation would be a round plastic jig that is perfectly round and has a hole in the center to fit different size bushings depending on the axle. The jig is placed with the axle through the center hole and bushing. The sheave then slides over the jig and the correct alignment is made. I felt that measuring from the rim would be wrong, and it always should be from the axle. The rear wheel could be out of alignment, but at least the sheave would be lined up correctly. This kind of jig would work with 24 and 26 inch wheels.
  4. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor


    Here are pictures of my sheave centering fixture, and the original factory bulletin from 1948 detailing how to use it.

    I have laced hundreds of wheels and this centering tool has saved me many hours of time installing the sheave.

    Have fun,

    Attached Files:

  5. Traveler

    Traveler Member

    Sheave centering fixture

    Thanks Quenton,

    I have a pretty well equipped woodshop. I may try to make a wooden version similar to yours