Every
now and again I build strange things out of bits of bicycle simply because
I can. It's got something to do with the massive availability of bicycles
and the ease and speed of reshaping them with a MIG welder.
One day I found this small bicycle
at the tip. Being a Raleigh it had proper metal ballrace bearings and not
the low quality plastic shells you get in so many kids bikes. I thought
it would be interesting to try lifting the whole thing by just a foot,
having seen pictures of adult sized Tall Bikes. Extending the front forks
was easy with a couple of suitable bits of hospital bed tube. Next I clamped
the frame upside down in a Workmate bench, suspended the back wheel between
two loudspeaker stands in what looked like the right position and fabricated
a new rear frame out of folding pushschair tube to reach it. Unfortunately
there are no photos of this as I was too busy concentrating on doing it
and I figured it had a good chance of finishing up back down the tip anyway.
In fact it nearly did because having got the wheel lined up the first problem
I discovered was that there was no way you could put a chain on! Luckily
some of the leftover pushchair tube included an interesting cranked bit
that I managed to weld in to weave the frame around the top run of the
chain. At this point a friend came round and took the first
photo. The cranked frame tube can be seen but there was still a problem
with the lower chain run. I solved that by making a spring loaded tensioner
using an old deraillier wheel and the thing started
to look as if it might work. Here's a closer pic of back
end. It was now looking as if someone might eventually ride it so I
decided to strengthen the back frame by putting in triangulated
braces. The next problem was putting on a brake, not simple as a front
one would be too dangerous and there was very little room at the back.
In the end I did manage to fit one in and then
had to spend the first bit of money on the project on a suitably long brake
cable for it. I decided a brace on the front
forks might be a good idea. Here's a later picture of the chain
tensioner using a locking bar from the folding pushchair and a spring
from a computer printer. This is the back of the frame
showing the bracing and the diversion of the top tube to miss the chain
run. Here's a picture of its first test flight
taken in poor light with a phone. Finally, this is a picture of its second
run in better conditions.
