Danny Colyer said:I never used to notice it, but now I often notice myself
starting a turn by countersteering. For some reason it's
much more noticeable on the Street Machine that it used to
be on my ATB. Perhaps it's more necessary on a bent than
on a wedgie.
Perhaps it's more noticable because of the lack of weight on
the hands & arms?
Last week, after reading the explanation of bicycle
steering in the 3rd edition of "Bicycling Science" I did
some experimenting. First on the Speed Ross swb recumbent.
I took it to a local industrial estate with a reasonable
area of concrete to play on. The bike would turn _either_
with a very gentle movement of the bars _into_ the turn or
with a positive push _out of_ the turn. A sharp push out of
turn generated a real feeling of instability as it first
went in the direction of the bars then reversed -- with the
rear tyre protesting. I didn't go too far with this,
falling off onto dirty concrete is not fun. Once in the
turn the bars were turned very noticably into the turn, but
had to held with a force out of turn. Letting go of the
bars instantly dropped it into turn, and to straighten up
the bars had to be pushed out of turn. At higher speed
corners on the road, I believe that the out of turn force
needed for constant cornering reduces, but haven't found a
suitable place the test.
Now on the wedgie (a Moulton AM). I really could not
detect what movements or forces were involved in getting
it to turn. Possibly because I was doing through weight
shift, but I think it was because the forces are so
light and considerably less than the loads due to body
weight. However, to keep a turn going it needs into turn
bar position.
Lastly a couple of motorbike experiments from some time
ago. To start the turn takes a definite push _out_ of turn
-- the classic countersteer. Push harder and the 'bike
drops into the turn faster. To straighten up push _into_
turn. However the two 'bikes behaved differently mid-turn,
one needed slight into turn bar position and the other
needed slight out of turn. Initiating a turn by weight-
shifting works, but slowly.
I am far from convinced that anyone (D G Wilson included)
has yet fully worked out all the factors involved in bicycle
steering...
Mike
