The California, Freindship One sidecar I purchased came
with a torsion type suspension which rotated a swingarm
against rubber elastomers in a square shaft centered on
the rotational axis of the swingarm. I chose to build an
entirely diferent frame than the car came with and also
to put a more adjustable suspension under it. The car body
I purchased is of fiberglass construction and unfortunately
has the wheel well preset such that when the car is level
and the wheel has about 3-4" travel, then the car rides
fairly tall beside the motorcycle. The reason this is a
problem is that if the car is riding tall, then the bikes
available lean angle is limited unless I move the car further
away from the bike. I started with the side of the car about
22 inches from bike centerline, which place the car wheel
about 50 inches from the bikes rear wheel. I test rode the
preliminary frame at these dimensions and it was a BEAR
to handle..I quickly cut about 6 inches off the outriggers
which helped exponentially on the handling.
Suspension: I built the suspension components such that
every aspect of it can be dissassembled and modified if
required. Self aligning bearing blocks suport the main suspension
axle with clamping colars securing the shock leverage arm
to the axle. A Honda CR80 shock exorber was purchased for
dampening. The shock can be fully adjusted for preload,
compression and rebound as well as interchangable spring
rates and Nitrogen charge. Parts are readilly available
for this off the shelf component. The leverage arm of the
suspension has multiple mounting holes for the end of the
shock such that the leverage applied to the shock can be
Materials: I originally wanted to fab
the tube car frame from aluminum, It would weigh about 1/3
the weight of a steel frame and could be as strong if the
right grade was chosen. After speaking to chopper builders
who use aluminum and racecar frame builders, I decided with
steel. I couldnt get a consistant answer from the so called
"experts" about the grade of aluminum needed.
And then there was questions about anealing it or cooking
it in an oven to remove all stress from bending and welding.
I found powdercoaters with ovens big enough and willing
to do it for me but there just seemed to be too much voodoo
and not enough clear written rules for me. I chose 1018
steel tubing with .120 thick walls in 1&1/8" dia
for the maincar frame. The outriggers were 1&1/4"
OD and .120"wall thickness. I didnt do any finite element
analysis(FEA) yet on the design but there is absolutely
zero flexing of any members while riding any terrain. My
design program has FEA capability with COSMOS, but I havent
had the time to learn the ins & outs of that yet.
Bending metal: Gary at Chester County
Customs bent all the steel tubing and TIG'd it. I took the
basic frame, mounted the suspension components and wheel
to it, then bolted the outriggers to the engine frame as
it was attached to the bike and then spot welded the outriggers
to the car frame. The spot welded frame was then taken back
to CCC to do the final TIG welding to the frame and add
the crossbar strut between the outriggers.
Once the main frame and outriggers were fabricated,
I took all the pieces to my garage and with the engine frame
bolted on the bike, I positioned everything in it's exact
position so I could tack weld the outriggers to the frame
in thier exact locations. This was a critical step as the
alignment and height of the sidecar depended on the exact
placement of these components. Many white chalk lines laid
out on my garage floor and checked with squares and tapemeasures
preceded the tack welds.
Steel plugs were weleded into the ends of the riggers,
they were both tapped to 3/4-16threads so the heim joint
threaded end could be screwed into them. The steel plugs
were welded inplace at the ends of each tube and a side
hole drilled into the outrigger and filled with weld front
the plug upto the outrigger outer wall for added strength.
I have 2 full inches of heim adjustment on each outrigger
to lengthen or shorten its length to set toe/in toe/out
Once the frame was welded, I positioned the car body on
it to lay out the body to frame mounting rails. I welded
3 cross bars made from 3/16 steel. Once in place the body
mounting holes were transfered and then drilled and tapped.
|Note the Cat on the bike is replaced with
a SS home-made tube going to a 916 Can
I had to buy a windscreen since the original was lost from
the owner moving the car from garage to garage during divorces.
Jay at Dauntless motors again was helpful and directed me
to windscreens. They had 2 versions of screens instock both
of plexiglass, one tall & one short. I bought the tall
one and it fit perfectly. I had to transfer the bodies mounting
holes to it and drill the holes to mount it. A special bit
is needed to drill plexiglass(The outer edges of the leading
cutting edge are ground back so it wont hang on the plastic
and crack it)and they sold it to me also.