An odd one yesterday - I rode the tandem with Ms Weasel, dropping her off for aerobics while I went off to buy our dinner for after the return trip.
On the way back to pick her up, on pulling to a stop at lights near Balham, the left hand side stoker's pedal fell off. On inspection, there is nothing obviously wrong with either the crank or pedal.
Does the pedal need lubricating more maybe?