What Type of Gear Shifting Mechanism Does YouBike Use?

It’s not a derailleur, but some other method. Never seen it before. Anyone know what it’s called?

If I’m not mistaken its a Shimano Nexus. I have a Dahon folding bike that also uses this mechanism.

It is indeed, http://taipei.youbike.com.tw/en/f41.php

Personally, I’m quite impressed with the Down tube: A smiley curve that is solid and easy to straddle upon. :slight_smile:

Internal gear hub