Originally Posted by bairdco
it could also be done manually. if you had a stacked sprocket set-up and a functional, spring loaded chain tensioner, you could easily stop, pull the chain off one sprocket and switch it over, letting the tensioner spring forward and back.
it'd be good for going from street to trail or flatlands to canyons, or wherever a lower (or higher) gear was needed.
i was thinking of my old Honda CT-90, '67 i think, that had a sprocket on both sides of the rear rim. for trails you had to switch the wheel around.
There you go. Would it be as good as or as convenient as a derailleur type of shift kit? Of course not, but is it better than no options? You bet it is! Just two sprockets to choose from in my case would do it. One for cruising at 25 to 30 and the other a bit lower for hilly riding with speeds of 15-20 or 20-25 or so would make a world of difference. Keep it simple, manual, inexpensive and bulletproof. It would be a winner and I'd be first in line to buy one. OK, second in line. Ferball is first.