I've got a 1981 R65 with about 300,000kms on the dial, never had a shaft drive problem. About 100,000 would have been on dirt roads, it always got a wash down as soon as possible after a trip - what else are pillions for?

Shaft drive, along with clutch centre failures are nearly always a rider/driver technique problem on any vehicle - ducks for cover - I know there can be batch problems once in awhile but those are quickly identified and often the problem is changed out at a routine service without the owner knowing. The less honest dealers will charge an owner if the bike is out of warranty (even though its a safety bulletin), getting paid by the manufacturer AND the owner.

The consumer demand for lighter shaft drive bikes, with greater carrying capacity will always mean that the manufacturers are pushing the limits - especially since the demise of old air cooled R series bikes.

Chain drives are a pain if you ask me, dirty, if you are carrying luggage that gets a fine film of oil as well, WHEN they fail it can be catastropic with the chain wrapping around the rear sprocket and locking up the wheel. The engine case can also get smashed with a failure or the front sprocket gets jammed and bang goes the gearbox along with it. I've seen other peripherals get smashed to bits as well - rear lights, indicators, pannier racks, battery, all making the bike hard to use if you are touring.