OK...so I need a challenge would really like to build a long distance capable recumbent tandem. So I'm going to build one from scratch. Just starting the project and expect it will take me through the winter to finish. The only design spec. I've settle on for certain is to use 3 eight foot sections of 1" ID EMT as the basic frame member. The bike will utilize the Bafang BBSHD mid-drive. Haven't decided on the voltage yet, nor the battery configuration, but I want to be able to ride the bike for an entire day and be able to cover any grade encountered without struggling. Will definitely include the Rohloff 500/14 tandem hub, with 26" wheels. For stability I'll be using the tadpole configuration. I'm hoping to be able to bring the cost of the bike in at less than $4,000.....we'll see!