Just to add to Hilary Stone's information, there was a variety of pressed steel calipers of generally less effective design than the aluminium kind. Some of them, the Phillips for example with its distinctive horizontal spring at the top, continued into the fifties. I believe they were used by BSA at one time and the British firm Ashby made an identical brake. As well as these, there was the rather complicated Monitor Supercam which looks as though it ought to work. (I will let you know when they are rebuilt and fitted to a bike.) Rudge, a company not known for doing things the easy way if they could complicate them, produced their own patented brake which was fitted on to the just pre-war range including their very desirable lightweights. BSA in the late forties made a flimsy one which seemed to make the cycle go faster when applied. It would be a pity if all these brakes were forgotten because they fall between two stools... too old for the lightweight enthusiasts and too new for the lovers of real veterans. Stuart Tallack from the little cycle shop at Amberley Working Museum in Sussex, England. "Don't trudge it, Rudge it!"