DrJim

You and I feel the same about Jimmy. I said they called me that, not that I liked it. They called me Jimmy as a kid and I too have cousins who still call me that. Not good. However, I still have a fondness for Dr Jimmy for some strange reason.

My guess is that others are getting sick of this Jim diversion.

Amesja

He did say they were unimportant questions...

DrJim

Good point. I feel better.

treebound 

It's only unimportant until something falls off, kind of like the medical field.

bradtx

Precession. That's the word I was looking for. Thanks y'all!

As for the straight legged forks, I suppose it's an aero thing, but visually lacks a bit of grace on a road bike to my eyes.

Brad

bradtx

For the 'Jims'. I had to look this up: https://names.mongabay.com/male_names.htm

Brad

jimmuller 

This place is a regular Jim-nasium. And as one of the Jims I'd say Jim knowsium what he's talking about. But this is waaaay off topic.

Mike Mills

You usually use the term precession when you want to describe a trajectory. I don't think the question is really about the path so much as it is about whay you would thread the device one way, versus another way. The answer to that has to do with the forces on the device, not the path of one object around the other.

I am not saying you won't see precessio. I am saying that precession does not answer the question.

DrJim

I can only say that you are wrong. Go get out your old physics book and reread the places where precession is discussed. I believe you will find that precession is not discussed at all in regard to trajectories but is a central feature in the discussion of rotating bodies. Look at any discussion of spinning tops for example. I assume you mean by trajectories the path that bodies take under the influence of gravity. The only place where precession might come into play there would be the rotation of spinning bodies such as bullets and shells.

In this case we are dealing with a mechanical phenomenon that is a precession. The animated diagram that was posted earlier is a good representation of what is going on and you might try the experiment I suggested with a pencil. I tried it myself just to satisfy myself. You can hold one end of the pencil loosely with one hand (make a little hole with your thumb and forefinger) and rotate the other end in a circle like I suggested. You will clearly see that the pencil rotates in the direction opposite to the direction that you are rotating the free end. That's what i'm talking about.

Mike Mills

I'm not going to engage in a pissing contest.

https://en.wikipedia.org/wiki/Precession

In the examples you cite you are talking about the movement of the pencil inside the ring or the direction of the spin axis of the top over time. Movement over time = trajectory or path.