[Dezmo]

Originally Posted by AZ Scott

So what is that limit? Do you really think that a wheel/tire/brake combo that weighed, say, 2 lbs. would make it so you couldn't turn the bike? How about 1 lb.? 3 ounces?

there is no actual number that you cannot go below, its a percentage of the bike's mass.

Originally Posted by AZ Scott

Okay, how much force are you talking about? Personally, I can get a motorcycle to flick over to full lean at 50mph by barely pushing on the inside bar. So how much "gyroscopic" force could I possibly be introducing into the system?

again, I never said gravity did nothing, but precession is what makes the reaction that quick.

Originally Posted by AZ Scott

You hold your lean angle by keeping the tire contact patches at the correct point in relation to the CoG. If you want a little more lean, you steer the front tire a little further away from the corner. If you want to stand it up a little, you steer the front tire toward the inside of the corner.

If you want to flick it from full right lean to full left lean quickly, you give it a nice firm push on the left handlebar. That causes the contact patch to move from the left side of the bike to the right side, and the rear tire contact patch naturally follows.

The center of gravity of the bike simply moves straight upward, and then back down as the bike changes direction.

This is why I used my downhill skier as an example earlier. To you, it's apples and oranges, but it's the same principle at work. Both things - a skier and a motorcycle - need to lean to turn. With both, the idea is to get the part that's connected to the ground to be on the outside of the turn. The skier moves his skis underneath him, and the motorcycle rider moves his tires underneath him. SAME THING.

Skiers fit perfectly into this explanation, but motorcycles are a bit more complex. You are correct about the movement of the CG, but if it was just you turning the wheel that made the bike lean/stand up, youd wear out fronts far faster than rear tires...not to mention youd need arms like a gorilla to steer a tire into the ground (if like you said, steering forces are what changes the lean)