On Wed, 18 Oct 2006 00:57:02 -0500, Solvang Cyclist
<
[email protected]> wrote:
>[email protected] wrote in news:41ebj2dqol5fbsan5s90v4fc5ogm1h4221@
>4ax.com:
>
>> So how do we balance on bicycles?
>>
>> Mostly by constantly steering the contact patch back and forth under
>> the center of gravity, which turns out to be easier with a long pole.
>>
>
>Thanks for the reasonable explaination Carl.
>
>However, this still doesn't explain why it's easier to balance on rollers
>than while stopped at a traffic light. Certainly gyroscopic action must be
>a part of the equation, although not the only part.
Dear Dave,
Actually, it does explain why rollers are easier than trackstands. The
secret is that the tires are free to move sideways on the rollers.
Stopped at a traffic light, you can't steer the contact patch from
side to side under the center of gravity. The tires are stuck against
the pavement by the tremendous friction of your weight pressing the
rubber against the motionless pavement.
On the rollers, there's plenty of friction, but the rolling action
unsticks the tire. You don't skid from side to side any more on
rollers than you do when rolling on pavement, but you can easily move
the tire sideways in both cases, something that you can't do while
stopped at the traffic light.
Ordinary riders perform trackstands by cheating slightly. We usually
**** the front wheel to one side. This helps in two ways.
First, the long contact patch on the front is placed at an angle to
the long contact patch at the rear to make a much better tripod:
-- / is much easier to balance than -- --
There are people who can balance no-hands just sitting on the seat
with the wheels straight, but we can safely ignore those miserable
sons-of--
Never mind. I get worked up about evil Chinese acrobats, who can do
handstands on bicycles standing motionless on just the rear wheel.
Second, with the front wheel cocked to one side, you can roll back and
forth ever so slightly over the front contact patch, rocking the
contact patch from side to side. Here's an exaggerated diagram:
/
-- / is really wavering from -- to --
/
It's even easier if the bike is heading slightly uphill, so that you
can rock even further back and forth. (Lower tire pressure is another
trick--it broadens the contact patches.)
Take away that little sneaky sideways movement of the front tire in a
trackstand, and most of us topple over.
Cheers,
Carl Fogel