2014,961. Only got 2700 miles on it. Had it for a couple of years but never rode it. (Moving house,retiring etc). Put it on the road 5 or 6 weeks ago. Got it motd. Bike is minted. Out for a run in the sunshine. Heading home. Downhill, 20 to 25 mph. Dropped a gear and then a thump/clunk. I pulled in the clutch and the bike died. No gears and no start. First British bike owned. I've got loads of Japs and Italians. Never had anything like this. Anyone any ideas?