So the handlebars seem to have come a bit loose on this bike and the nut on the clamp bolt is 13.4 mm across the flats which is approximately 17/32 in. Why on earth is that? Did Brompton have some sort of proprietary nut size made? Or is this some sort of obscure British standard like Whitworth?
https://en.wikipedia.org/wiki/Britis...dard_Whitworth