C-FAUK
My wheels are rear from Honda motorcycle
from a CB 350. They are similar in the CB250 and CB450.
This is how to modify them for use on an
Air Camper.
Wheel bearings
Remove the ball bearings from wheel and
discard after measuring the outside diameter.
Make bronze bushings (4) with the same
outside dimension and width (add 0.05� to width) as ball bearings with an inside
dimension of 1.5�
These bushings should be a press fit
into the hubs like the original bearings. They should be slightly proud of the
wheel when installed.
Modification to Wheel
Remove the spokes from the wheel rim and
hub. Remove the sprocket nut and sprocket.
Install the hub on a lathe and remove
the threaded piece that holds on the sprocket. It is a steel piece that is cast
into the aluminum hub. All the steel is removed but be careful here. You are
facing this hub so the bearing cavity is the same width as the bearing cavity on
the inside of the hub.
This step can be done without a lathe by
hack sawing the steel piece off and filing or grinding the hub so the same
dimension is achieved as above. As long as when the bearing is installed the
bearing is slightly proud then the job is done.
Cut off the casting lobes from the
inside of the hub with a hacksaw. This will be obvious. Reassemble the hub and
rim.
I used a 18� by 3� tire with about 45
psi air pressure. Your rim may be different as some of them were 16�.
Modification to the brake plate (see sketch)
You will need to make four aluminum
collars to fit on the 1.5� axle. I
used 2.5� O.D. by 1.5� I.D. aluminum pipe and they are about �� wide.
This pipe is commonly used as
scaffolding tubing and is 6061-T6.
You will need to make two transition
pieces for the brake plates from the same material. Dimension as needed below.
First remove the brake shoes and
hardware from the brake plate. Install it in a lathe and bore a hole the brake
plate just slightly smaller than the outside diameter of the aluminum pipe. Face
off the feather edge enough so you can later weld this plate to transition
piece.
Now machine some pipe material so it is
a slip fit with the hole in the brake plate. There needs to be a shoulder on
this piece so the piece projects through the brake plate to the same position as
the unmodified brake plate did. In
another words the transition piece must hold the brake plate in position in the
same position as before with the smaller axle. This takes the side thrust and
prevents the brake plate from contacting the wheel.
Once the step is done the transition
piece can be parted so that �� of the transition piece projects out of the
outside of the brake plate.
Put the pieces together and carefully
align. Weld the transition piece to the brake plate.
Drill out the hole in the brake plate to
�� where the anti-rotation arm attached. Install a piece of heavy walled steel
tubing with a hole to attach a cable.
Cut off the brake lever and drill a
3/16� hole in the end. The lever needs to be only about 2� long!
Installation
Braze one or more small but thick pieces
of steel to the axle to prevent the inside collar from siding inward. This is
better than drilling a hole in it. Don�t fret about this the bungles tend to
push the brake plates outwards
Install the inner collar, the break
plate, the wheel with bearings and the outer collar. The outer collar is bolted
to the axle with a 3/16� bolt.
When installed the brake plate must
rotate on the axle.
Anti �rotation Device
Flatten an end of
�� tube and drill 3/16� hole in it. The flatten end will be bent slightly
so that part is vertical when the piece is installed.
Install the tube to the front of the
gear leg with a steel strap. File a small grove in the bottom ash piece to help
it stay in place. Close off the top of the tubing.
Install a cable between the tubing and
the brake plate tubing about 6� long. The cable is 1/8� diameter.
This looks Mickey Mouse but works very
well. I wish I could take credit for it but I copied it from a picture of a
Californian Piet.