If you are interested in a new velomobile gearing technique, have a look at https://www.youtube.com/watch?v=-LIyl4aGpac. This allows almost all the drive mechanism to be inside a velomobile body, out of the dirt and dust. The mechanism was developed by Drymer and Sinner Bikes. The Drymer-Sinner Hilgo velomobile will only set you back 7,750 Euros.
- Two front chainrings; 34 –50T;
150mm SD-cranks standard o Shorter cranks are possible
- Shimano 105 11-Speed front derailer
- 11-speed chain KMC
- Sunrace 11- speed 11-40T cassette
- Shifting system developed by Drymer - Sinner;
o Super light shifting
o Super fast shifting
o Intuitive handling
o Wide gear range
o Drop - in mid-drive axle
o Optimal chain tension in every gear
- Sturmey-Archer 70mm drum brakes
- Front light; Busch+Müller IXON- X E 150LUX mounted in the nose.
- Interior LED light
- 1 PC. Battery 12V
- Tires; Rear maximum 55-406; Front maximum 44-406
- Suspension; McPherson front struts, rear Hilgo shock absorber. (maintenance free)
- Self supporting, removable seat (glass fiber)
- Cateye Enduro 8
- Wheel covers black
- Mirror Zefal Spin
The way of the future in velomobiles? The Hilgo mechanism indicates a departure from typical bicycle engineering parts to purpose velomobile stuff. The derailleur system looks like it is a push-me-pull-you affair with two cables. Easily replaced with a stepper motor? Now there's an idea. I don't know if there is any cassette on the rear wheel. Possibly not as there are 22 gears available in any case. Note that the mechanism has a modern MTB cassette with a 40t lowest gear. I love the chain tensioner.
Also have a look at http://hilgovelo.blogspot.com/2017/11/the-hilgo-story.html for the development story by one of the Sinner people - Harry - to get a greater understanding of how good it is. You will see that it is shifted by two cables.
Now, can I come up with a home-made variation that I can swap in before I get too far advanced? It seems simple enough. Is there yet one more velomobile to build?