Spotted this wierd thing in an access archway - it appears to me some kind of mutant push-trike.
Brian's bike: he had a fellow rider crash into his back wheel at a set of traffic lights (!) and his gear change went a little adrift, so we had a quick look. Fortunately I looked at the front of the bike as well as the back. The gear cable felt a bit iffy so I looked inside. It was down to two or three strands.
This happened as I pulled the cable through. Phew - caught it in time. This was a brand new cable only a couple of weeks ago, I guess the collision with his derailleur pulled the cable back hard enough to break the cable..