Lets try inverting the myth about some of the frames with unusual geometry built in Britain.
As we know that they were being built before the "Cycling" ban on photos baring a frame name, perhaps the ban on such photos was a result of pressure or inducement from the builders of that time who did produce unusual frames?
The editorial staff responded to the pressure and or inducement and hid it under the pretence of upholding amateurism, as was the fashion of the day?
Strange as it may seem, even to Sheldon, some frame designs did come about due to attempts to engineer improvements.
Bates cantiflex tubes were born out of the desire to use larger diameter tubes. They were thwarted in their efforts as they could not get the lug casters to supply quality lugs to fit the tubes. So they took a new approach and asked Reynolds to draw out the centre of the tube, giving an oversized tube in the centre but allowing the use of regular sized lugs.
Are oversized tubes an improvement? Most tubing companies and frame builders, of today, using their huge armoury of stress analysis and computer modelling, seem to think so. Some of their modern frame attempts even look like Gillots and Granbys. Frame design by evolution.
Why do 531 tandem tubes have an ovalised connecting tube between the two BB shells? Answer, it is the biggest area of join you can get on to the shell. Conclusion, not all design is based on the materials or their form but on the way they can be put together with what is available.
I believe the modern rush towards greater and great oversizing in aluminium tubed frames was held back in its early years by the size of front changer clamp that was available.
It was interesting for me to read, on this list I believe, that the "Columbus" tubing manufactures were the first company to produce variable sized cycle tubes, first doing so in the 50s. Their literature forgot to add "in Italy".
One last point on frame design. Why do Bates frames have Diadrant forks? Answer, because their was a butchers shop next to the original frame building shop!
Regards Martin Coopland, in a cool and blustery Larbert.