Chain Monkey

[fritzwilliger_imp]

I don't understand how it works? You'd think they would have shown from the side what is happening as you adjust the chain.

I, too, was not completely sure if I understood what the Youtube video was intending to demonstrate. What I THINK was the intention is the following:

The Chain Monkey Tool is designed to "dial in" a certain amount of chain tension corresponding to each specific bike by making use of the curvature created inside the tool so that when the rest of the chain extending to either side of the tool becomes flat and straight (via whatever adjustments are required at the rear axle) and the Chain Monkey Tool is then removed, the proper chain tension is already "dialed in" as it were.

Hope this helps.
fritz