explain to my six year old why it's harder to balance on a nonmoving bike than one that is being pedaled?
I've tried my usual bad Dad approach of "look it just is, keep pedalling" which is helpful on one level but it would be nice to tell him a bit more.
Gyroscopic effect - get him a toy gyroscope or take a wheel off and spin it and show him how it likes to stay in the same place
Show him a no-hander riding.
Then show him a no-hander track standing.
roll a wheel along the road
Falling into a corner against falling over.
Ah. But why is it easier to balance at very, very, very low speed than it is stationary? Can't be the gyroscope effect because there's so little of it...
Gyroscopic precession effect actually increases again as the wheel reaches very low speeds. Can't remember exactly why - lots of vector maths / physics involved - but it just does. That's why navigation gyros can 'topple' as they are slowing down.
[url= http://en.wikipedia.org/wiki/Precession ]Gyroscopic Precession[/url]
Gyroscopic effect - get him a toy gyroscope or take a wheel off and spin it and show him how it likes to stay in the same place
Except that's not actually how you balance on a bike - has been proved by making a bike with counter rotating wheels to cancel out the gyroscopic effect, which was then still perfectly straightforward to ride.
The real answer is that when you are moving you can steer to move the road contact points back under your CoG if that moves to one side or another of the centre line. When stationary you can't do that. Not sure I'd like to try explaining that to a six year old - though it might be slightly easier than explaining gyroscopes! The simplistic version is I suppose that you can steer to balance when moving, but not when stationary.
I am with chrism on this one, try a balance bike or a bike without pedals, and get him to notice himself moving around to keep his weight top side, putting his feet down to do the same
Hey what are we all doing its sunny outside.......!
Just put it down to Daddy Mad Skillz