Tandem with Fichtel & Sachs Torpedo Automatic gear hub
I found a 30 year old 26″ Tandem with a Fichtel & Sachs Torpedo Automatic hub on eBay.
The interesting thing is that the hub is designed for the power of two cyclists! That means there is a much higher mechanical spare inside the hub. The static weight of two riders and the momentum into the hub is doubled here!
This is one reason for the long durability of the hub.