Ron,spinningmagnets wrote:This thing is bugging me, and I really want to understand it...
Part 10 is contiguous with the ring gear.
Part 18 is contiguous with the spur gear.
Both are in permanent engagement with the minor planet gears.
Because one is an internal gear, they will rotate in opposite directions.
The ring gear  will rotate in the same direction as the planet gears.
The spur gear  will rotate in the opposite direction.
Part 13 is connected to the hub shell.
From the perspective of the drawing:
If the motor is rotating in a anti-clockwise direction, the planets will rotate in an clockwise direction, so part 10 will be moving in a clockwise direction which will cause the rollers to lock it to part 13. So, in this case, the output will be from the ring gear, so we are in first gear. The spur gear, which is also engaged, will rotate in an an anticlockwise direction, so it will not force the rollers to lock it to part 23, which is connected to the hub shell via part 13. It will simply rotate on bearings mounted on the central axle and not be in the active output chain.
Reverse the rotational direction of the motor and the roles are reversed and second gear is active.
Does that help?
Edit: LOL. You posted your additional thoughts while I was writing mine...