The chain drive is more because of the frustration with the belt than anything. My steel rear sprocket has been on for about 24,000 miles now and it doesn't look as quite so pristine these days. The belt was replaced about 7,000 miles ago, not that it was worn out but because I had the swing arm out and the other belt was a bit squeaky at times, it had eaten a few alloy sprockets in its earlier days. The belt drive seems to be requiring more adjustment and cleaning to keep it quiet than it has in the past and has to be spot on, not just close.
The chain drive kit works out considerably cheaper than a new steel rear sprocket and belt and there is some scope for ratio adjustments, lighter, better clearance for the tyre, easier alignment and more tolerance of misalignment and I just fancied giving it a go. If it all proves to have been a mistake, not that I think it will, it is fully reversible back to the belt drive. You even get a slightly better transmission of power with a chain over a belt. Downside is maybe more maintenance but that won't be a big issue with the annual mileages we do, I quite enjoy the maintenance anyway. It will have a chain guard and maybe some Kevlar under the luggage tray as well, just in case.
Got it, Planeut! Thanks for that explanation and I look forward to hearing your observations. My mental breaker needed a reset after having migrated from chain to shaft-driven motorcycles and still listening to Ducati's rattle to a stop. Anything that adds MORE noise to the 3W would need a 'plan b' in my book. But this sounds like a worthy experiment.
