NOTE: All Motobecane model references are to European models. There were differences for North America and maybe some other markets and I will add an addendum on those if someone with the necessary knowledge cares to write it.
From 1970, maybe before, the top of the line Motobecane racing bike was the Tour de France model built with Reynolds tubing up to and including 1978. All, as far as I am aware with Campagnolo components. From 1969 to 1973 this was the production version of the orange Bic Motobecane team bikes. Here is a link to a 1971/2 and here is a link to a 1978 Motobecane Tour de France model. The 1978 is totally original with lightened Campagnolo Nuovo Record components: The 1971/2 has been built up from an acquired frame, but is believed to be to the correct specification. Motobecane did not sponsor a top level racing team during the years 1974 to 1978 inclusive. In 1979 they co-sponsored the La Redoute Motobecane team.
1979 was a new departure for Motobecane. The top level production racing bike was the C5 built with Columbus tubing in place of Reynolds used previously and French components. the distinct differences from before were: Huret dropouts, the RH rear incorporating the gear cable outer stop. With Huret dérailleurs, Stronglight/Spidel crankset, Laprade seat post, Philippe handlebars and stem and Weinmann Carrera brakes.
Motobecane also hand built made to measure racing bikes similar to the C5 and this was the basis for the “Special Pro” and La Redoute Team bikes which signalled Motobecane’s return to top level racing. The major differences from the C5 were: racing number tab at fore of top tube; initially Stronglight/Spidel 105 crankset with silver anodised chainrings in place of black anodised, and later Stronglight/Spidel 106 crankset; Cinelli handlebars and 1R stem in place of Philippe; and Weinmann Carrera 400 brakes in place of an earlier type of Carrera brake.
The La Redoute team bikes were the same olive green colour as above. The decal colour of the team bikes is not easy to discern from racing action photos but certainly some bikes seem to have the same as shown in the publicity photos as below and which I am in the process of having reproduced:
