I saw a couple of speed record attempt machines in a French museum - MASSIVE chainwheels ... apparently the rider had to pushed to start by a bloke on a motorcycle with a thing that looked like a broom pushing against the bike saddle. Can't remember the speed attained.
Sadly the museum, at Cormatin in Burgundy, is no more.
AND just before the M42 south of Birmingham opened there was a cycle speed attempt with a big chainwheel - I think the rider was following a Rover SD1 with a shield on the back to get up to speed before the car pulled to one side. Must have been quite a sight.
Rob