I posted this on the recumbent forum but didn't get much response maybe you guys can help. I recently got a 2002 Rans Rocket that is stock. I want to know if any one has ever added an internal hub and kept the front derailier. I figure that if you add a sram dual drive 24 hub, cassete and dual right hand shifter you can keep the regular sram 7.0 derailier. Then you can run the middle chain ring and use the rear hub for shifting except for up and down hills where you have greatly expanded your range of gearing. Just an Idea also I figured I could put a better "off-road" tire on the old wheel for use on rail trails and such where you don't have hills to go up and down and don't need the gears. Because the Rocket has a 20inch rear wheel and large chain rings you don't put any more torque through the hub then you would in the regular dual drive set-up. Thanks Milky
Sram web site

Catrike does something similar on their trikes. I'd say that you should be able to do this. If it works out, let me know, since I'll want to do the same to my Vision R40.