Let the brakes off and reapplied to try to get some grip whereupon a horrid clunking crunching clacking sound came from beneath me.It sounded like a cross between dropping it into first gear without the clutch and rattling a tin bucket of spanners around.It lasted about a second, scared the crap out of me as it was loud and I'm sure I felt the bike jump, like it had gone over a speed bump.
The chain and sprockets could be original so they've done 18500 miles. Bike serviced at main dealer at 16000 miles.The chain was covered, and I mean caked in waxy crap when I got it and I cleaned that off to reveal a nice gold link chain.