I reckon the duomatic equipped bikes are the best round, do you agree John? I love riding the AM2 about and particularly enjoyed my MK3 / AM hybrid with duomatic, now fitted with the 5 speed SA hub and bar end shifter. I have always wondered how it worked with those mudguards on the Marathon, it always looked to be centred up nicely on pics from the period, although I would expect that there would be a fair amount of space required to slide the wheel back and forth!
Does anyone know exactly what sprockets were used? It seems a novel way to add 4 gears in effect, wonder how easy it really was though, with a laden bike and being absolutely knackered after a long day in the saddle?!
Tom