Jerry asked about a source of information on the French technical trials. Bicycle Quarterly covered these in great detail in Vol. 1, No. 4 (pre-war) and Vol. 2, No. 1 (post-war).
The short story is that the "disciples" of Velocio were unhappy with the bikes the industry provided. In the early 1930s (similar to today), the focus was on racing, or utilitarian designs. To move things in the direction they wanted - better performance, lighter weight, improved durability - these cyclotourists organized the technical trials.
Bikes were entered by the makers, and the entries had to conform to the rules (minimum tire width, fenders and lights were required, bikes had to carry a load). Points were awarded for features considered desirable (wider tires, short chainstays, front derailleurs, and above all, light weight). Then the bikes had to be ridden for 300-500 miles over really rough roads in the mountains in four stages. After every stage, the bikes were checked, and points deducted for broken parts and other mechanical problems. Points were awarded for high average speeds, because a faster rider challenged the equipment more. Whoever had the most points at the end won - that is, the maker, not the rider. There were different categories for bikes and tandems.
Winners included Reyhand, Barra, Narcisse and Singer pre-war, and Singer, Herse and Routens post-war. The trials required builders to push the limits of design and light weight, while keeping the bikes reliable and durable. The result were the amazing bikes from these constructeurs. Jerry is right, a 1940s technical trials bike, complete with fenders, lights, racks and wide tires weighed 8 kg (17.6 lbs), significantly lighter than a Tour de France bike from that era. Even the production randonneur bikes from these makers were lighter than most racing bikes. The 1947 Singer, in a 60 cm frame, with 38 mm tires, full fenders, front and rear racks, full lighting and a pump weighs just 23 lbs.
The technical trials led to the development of cantilever brakes, low-rider racks and cartridge bearings in hubs and bottom brackets, as well as other features still used on bicycles today.
Jan Heine
Editor
Bicycle Quarterly
Seattle, WA
http://www.bikequarterly.com