I think that may be the best way to go AQM. That said, there is a local chain specialist who says he will have a look at my M3W with a view to a chain conversion, if a durable belt drive proves just too difficult. The chain drives generally seem to have steel drive gears and alloy sprockets with no big wear problems and changing ratios is easier. A guard would help reduce wear from grit contamination greatly, it gets pretty dirty back there even with a mudguard fitted.
