Interesting fact about a wheel.

[Mikkel]

I would say if you had another identical wheel rotating at the same rpm in the opposite direction then the momentum of the top and bottom halves would be the equal.

Are we talking about momentum or angular momentum?

Bottom halves, top halves, that's the part that doesn't make sense. It's a wheel for christ's sake... Not two hemi wheels or something else, it's a wheel and should be treated as such.

Unless of course you're not interested in the mechanics behind the motion...

[GSVR]

Are we talking about momentum or angular momentum?

Bottom halves, top halves, that's the part that doesn't make sense. It's a wheel for christ's sake... Not two hemi wheels or something else, it's a wheel and should be treated as such.

Unless of course you're not interested in the mechanics behind the motion...

I am ignoring any vertical displacement as these are equal in this case.
So out of any angular value your only taking the horizontal component. The same direction as the bike in negative or positive values but all positve after combined with the forward displacement.

[Mikkel]

I am ignoring any vertical displacement as these are equal in this case.
So out of any angular value your only taking the horizontal component. The same direction as the bike in negative or positive values but all positve after combined with the forward displacement.

Que?

Just tell us what you're trying to achieve and stop trying to make sense, because it doesn't work.

[GSVR]

Que?

Just tell us what you're trying to achieve and stop trying to make sense, because it doesn't work.

Experiment:

Lets set up a 17 inch wheel in a cradle that can pivot the wheel horizontally about and axis that goes through the centreline of the axle from front to back of the wheel maybe ever so slightly above center.
Place this in a train moving at 100 kph and spin the wheel at 884 rpm. Now move the entire cradle from side to side in relation to the forward movement of the train . What happens?

[Mikkel]

If you only move the cradle from side to side - the wheel will sit rock solid in the cradle not tilting or changing it's direction of rotation.

[Finn]

Think we should all delete this as its a bit off topic!

Dude, your bike is off topic.

[marty]

so the 250-odd g's, causing substrantail centrifugal stability, would react in what fashion when i input a force to the axle 90 degrees before i want the reaction to happen?

[Patch]

Since when did KB ever start being on topic with anything??


stop being a farkin whinger otherwise we'll shrinkwrap ya, and send ya down to Dunedin with all the rest of 'em

[Steam]

...send ya down to Dunedin with all the rest of 'em

Eh wot?? Bastidge!

[Steam]

EDIT: OOps, posted in wrong thread.

Look, GSVR, the whole wheel has the same momentum, it just looks like the top half has more momentum when you do the calculations as you would with the ground as your frame of reference. This cannot be done.
The calculation must be done with the axle as the frame of reference, then the thing becomes clear - the whole wheel has the momentum, not just one part of it.

[Steam]

What are you on about? Are you sure your posting in the right thread!

OOps!
You are right, wrong thread.

[Mikkel]

Can you delete all of it then as otherwise this will end up in senseless drivel

Why bother with deleting it. I doubt anyone is going to find this thread "prune"-worthy.

Either it dies from old age or gets relocated to PD.

[GSVR]

If you only move the cradle from side to side - the wheel will sit rock solid in the cradle not tilting or changing it's direction of rotation.

Made a drawing. The sideways movements will be reasonably forcefull over say 1 metre.

[Badjelly]

Cool you just said it. Now which instant are you talking about because every point in time is an instant in time. So you are actually saying all the time.

Yes, all the time. But it might be worth remembering that the "top half" and "bottom half" of the wheel that we're talking about at one instant will not be the top half and bottom half a short time later. Then again it might not be worth remembering: it depends (again) on where you're going to go with this argument.

[Mikkel]

Made a drawing. The sideways movements will be reasonably forcefull over say 1 metre.

If you only move the cradle from side to side - the wheel will sit rock solid in the cradle not tilting or changing it's direction of rotation.

There's your answer.