ProjectVF - October
2007
I spent hours hours designing
and building a cable-based steering mechanism. I made tie-rods which
connected the forks via a pair
of rocker arms, which in-turn pivoted on the bolts used to hold the upper
A-arm. I liked the way the rocker arms worked, so the cables and bushings
seemed like an easy way to tie them to the handlebars.
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Here's a close-up of the tie-rod and rocker arm assembly. To eliminate any
bump-steer or binding, the pivots of the tie-rod must be aligned with
the pivots of the control arm, which this achieved. The
drawback is that when you
pull on the top of the rocker arm, the bottom pushes in the opposite
direction, which makes the steering backwards. A pulley connected to the handlebars seemed like an ideal way to
correct the movement, so I started building.
Here's how it looked from above. On paper it seemed feasible, but in reality
the cable kept stretching and the bushings didn't want to rotate. Worst of
all, it felt more like a carnival ride than a motorcycle. It was also tough
to build but I became a better
fabricator so I guess that's my reward.
Out of money, back in an office,
and watching the arrival of Winter, I admitted failure and scrapped the
unworkable mechanism. This is the cost of a trial-and-error design, and now
it's back to the drawing board.
