Center of Gravity opinion....

# Thread: Center of Gravity opinion....

1. ## Center of Gravity opinion....

A discussion on the center of gravity.....

http://www.msgroup.org/Tip.aspx?Num=142&Set

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3. I didn't know that was a common misconception.

I thought it was fairly obvious if you take a very heavy object like a head and torso with gear on and place it MUCH higher off the ground by standing on the pegs; the cg will be affected in a negative way.

4. I didn't read that thing yet.

But there are other factors at play with center of gravity when you add motion and mussle movment instead of a stationary thing.

Basicly if you push down on your peg the force of your mussles pushing down brings the center of gravity lower into the pegs, kinda like when you jump in the air you become weightless to a scale for a breif period of time but you excerted force to the ground to do that jump

dunno if that makes any sense

6. Originally Posted by Dustin2
I didn't know that was a common misconception.
Neither did I, assumed it was common sense....I think it is actually.

Just because one guy writes a long winded diatribe, stating the obvious, simply means that he didn't know himself.

7. good topic. i have read that the high centre of gravity of sport bikes, dirtbikes, etc. is exactly what gives them good maneuverability.

i have also read about manufacturers, accessory makers modifying things to move the centre of gravity down as if this is somehow advantageous.

Which is it?

this is different from 'mass centralization' which is a different, if related, kettle of fish. (u can centralize the mass high or low, in other words)

8. There's a few things going on here. First of all, to 3DDeath's point:
The point of application of force does nothing to change the center of gravity. The center of gravity is at the center of mass, and that can be thought of as the 3D balance point of the bike/rider system.

When rider stands on the pegs, a few things happen. While it is true that the center of mass of the bike/rider system is now higher, remember that the rider is also less coupled to the bike. A moment force acting on the bike can now move/tilt the bike without moving the rider's center of mass, certainly more so than when the rider's butt is planted on the seat, and the overall effect is probably that the bike feels more stable since the bike is moving more w/o transferring the motion to the rider.

I truly digress here, but here's an interesting point to what you brought up 3DDeath. If you were in space, holding onto a heavy ball, and you threw the ball...you realize that the center of mass of the 3DDeath/Ball system will actually remain the same even as the ball travels forward and you travel backwards?

9. Interesting point Kivyee, with your ball in space theory, your kinda correct but really the center of mass should change once the object seperates since they will now both have their own center of mass.

More like your first point, for example if you jump of the bike, your bike now weighs 180lbs or so less and the center of gravity drops down, all because you no longer have an effect on the bike. (till you land back onto it)

good topic. i have read that the high centre of gravity of sport bikes, dirtbikes, etc. is exactly what gives them good maneuverability.

i have also read about manufacturers, accessory makers modifying things to move the centre of gravity down as if this is somehow advantageous.

Which is it?

this is different from 'mass centralization' which is a different, if related, kettle of fish. (u can centralize the mass high or low, in other words)

A Low or Centralized mass means there's less mass shifting during operation. If you add weight up high the bike "falls" into corners and wants to continue to fall. If you lower CoG the bike has less mass and inertia to continue falling into a corner. If your mass is centralized there's more predictable handling. If you place a bowling ball on your tip, tail, or side various weight shifts would cause poor handling.

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