burly makes some nice pull trailers at a reasonable price and work great towed one on a 600 mile bicycle trip through the Oregon cascades (MTB not a MB) nice and light tows like a dream. planning on towing it with my MB to grocery shop. on the duel gearing used to be a mechanic on the great Arcata to Ferndale kinetic sculpture race and we did a split rear end for pavement and a lower gear for sand we took a 10 speed crank arm cut the arm off and used a deraler for a tensioner and to shift up and down. don't know if thats gives you any ideas but hope it helps. I'll be rooting for you!
