Build Log

I studied frames from the 20's and early 30's to get as close the the correct dimensions as possible. I soon realized that using the Yamaha frame would bring a few compromises. The neck angle and the bottom lower horizontal rails were set from the factory, I had to work with this to get as close to the look I wanted. After establishing the wheelbase I began to draw out the frame. These were my dimensions:

  I made 2 mounting locations for my frame table to hold the frame. Each were T-style vertical box tubing clamped to the table at each end,. One would anchor the rear axle plates and the other would be the Neck Jig.

These were the stock Yamaha axle plates, just covered with body filler.

Using a 4'' Grinding wheel I removed the plastic filler and
cut off the pipe from the previous owners hardtail.    

These still needed cleaning up but I decided they were worth re-using

Rear plates mocked up in frame jig holder

Another view

The neck half of the frame jig presented a challenge. The last thing I need in a small 1-car garage is a large welded frame jig taking up space. So I used the same type of tubular steel 'T" frame for the neck, welded a pivoting threaded rod and began making the Neck half. I used the drill press to turn wooden half moons to fit the neck bearing cups. Then I drilled through the center for the threaded rod to pass through, large washers were added on top and bottom and it was capped off with a nut.

Lower pivoting area, frame neck is on left top, jig half is on right.  

Getting a view of the frame, I used this pic to sketch
some rough mock-ups. See below.

18'' wheels and an Indian type Leaf Front End. See the compromise in the front down tubes.
They run at a different angle and get horizontal too soon.

The jig was holding the frame well. time to set the wheelbase and height.

I had the engine and trans mocked up earlier, you can see my notes on the table top

 Lower rear legs were bent and slugged.

The inside width between the rear axle plate was narrower than the lower front down tubes. You can see how the tubes had to be brought inwards to arrive the correct point.

Engine mocked in place, note silver conduit used
for test bend of lower legs.

Checking rocker cover clearance with frame top backbone

18'' Rear wheel from Honda CB200T

Ford Model A spare tire cover with stainless moulding.

Front Wheel  form Honda CM200T, Rotor disc removed.

BSA A10 4-speed transmission test fit-up.

Center seat post set in position, this post has a 15 deg bend midway down