ProjectVF: How This Got
Started
I wanted to build a three-wheeled,
street-legal vehicle powered by a motorcycle engine. I made countless
drawings of various configurations. At right is a 1/10th scale model built
entirely from poster board and hot glue.
While searching for information about
three-wheelers, I started noticing recumbent motorcycles. Many were built by ordinary
people with limited budgets but their results were incredible and looked
like a lot of fun, which got me thinking.
I looked for something bigger and
found this Yamaha XS650 for $500. It was dented and beat-up but the motor
ran great. It turned out to be dependable and fun to ride. Being a vertical
twin it had lots of torque, but vibrated quite a bit, and ducting for the
air cooling would be difficult, so I sold it. I managed to get my $500 back
and gained enough data for the
crude photo simulation below.
At left is a very old Honda
CB200. Although low on power, the engine was
dependable and economical, so I considered using it as a donor. I did some simple CAD drawings but
the bike was just too small for practical use and was later sold at a garage sale.
This composite photo shows how
my design was proceeding, but the ductwork was ridiculous: I needed a bike
with water cooling. Being the owner of a Honda VF500 with a smooth and
powerful V4, I began looking for another one. I also looked at Sabres and Magna, which feature the
same V4 design (up to 1100cc) and shaft drive.
Here's an 1100cc Magna, just
begging to be cut and and modified, but at $2800 it was a little pricey for
my budget. The largest Interceptors were 1000cc but not many examples
remain. However, 750cc models looked plentiful and the prices were low. I watched CycleTrader.com and eBay and one day was rewarded.
Here's the '83 VF750 I bought from a local
seller. The bodywork came in a box and was promptly resold. My total cost
ended up about $350. I never tried to start it and expect the motor to be
whipped (the camshafts are pitted and scored), but this was what I needed
for dimensional data.
Wiring stripped, hand controls gone, and radiator
removed: what's left is the bare essentials. I hung
a sheet behind it for contrast and took a series of photos. You can see a
tiny checker-pattern at the rear which was used as
a reference for scaling the photos in my CAD software. With a good
photo and the correct scale, I was able to easily and quickly trace the bike with 99% accuracy.
With good data and the bike drawn
up, I can try endless variations without spending a dime. Beginning with the
green tracing at left, I adapted the Interceptor to my needs, creating a
rough design to get the project started.
