I did some research and pedal section( bottom bracket) gears exist, but aren't very common. http://bicycles.stackexchange.com/questions/8872/bottom-bracket-wit

I did some research and pedal section( bottom bracket) gears exist, but aren't very common. http://bicycles.stackexchange.com/questions/8872/bottom-bracket-with-built-in-internal-hub-does-this-exist http://bicycles.stackexchange.com/questions/8872/bottom-brac... http://www.haberstock-mobility.com/en/products/schlumpf-drive.html http://www.haberstock-mobility.com/en/products/schlumpf-driv... http://bicycles.stackexchange.com/questions/5274/why-not-have-the-gears-inside-the-bottom-bracket http://bicycles.stackexchange.com/questions/5274/why-not-hav...