Quote:
Originally Posted by utopia
Surely the bike must rotate laterally about the tyre contact patch, not the centre of gravity ....?
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No. Newton’s first law is ‘an object either remains at rest or continues to move at a constant velocity, unless acted upon by a force’, so ignoring friction and air resistance a moving bike will just continue straight down the road till you (Or something else) does something. If you want to turn a corner you have to do something with the steering. For a right hand bend you need to get the bike leaning, so you have to steer LEFT. Only long enough to get the bike leaning. Effectively that steers the wheels out from under you. If you want to check this, try steering a heavy bike with very short clip ons. The steering effort on the bars becomes quite noticeable.
Once the bike is leant over you don’t have to steer. You could go “no hands” if you wanted. The bike will just carry on in a circular curve until you change things again.
To pick the bike back up to vertical you have to steer the front wheel back under you. The back wheel just follows it.
If you want a practical demonstration, try making tyre tracks with a push bike when there are some puddles. You can see that the right corners start with the front wheel steering to the left, then swinging round to the right once you are leaning.
Quote:
Originally Posted by utopia
In order for it to rotate about the C of G, the contact patch would have to move laterally on the road, would it not ...??
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Yes. It does.