Mecacycle Turbo - St Etienne France

The Turbo range was very popular in France, in the 80s, as were twin seat tubed frames in general, with examples being made by GELIANO, CACEG, and AMR, and Motobecane. Surprisingly the cyclo-cross version was particularly popular due to the fact that the mud and crud did not lodge between the tyre and the rear of the seat tube...a very free-running design. In spite of looking quite fragile, very few Turbos appear to have broken. The manufacturer claimed that the twin-tubed structure conferred a greater rigidity to the frame. from here- http://www.flickr.com/photos/cyclecrank/

A "TURBO" low-profile track frame made by MECACYCLE of St Etienne in the mid-80s. The main feature of the "TURBO" frame was the use of twin aero section fork blades used to replace the seat tube, enabling the rear wheel to pass between them, thereby producing a rear triangle of 37.5cms.. Various tube sets were available and the frame could be built for road track or time-trialling in low-profile or standard design. Early models had the tips of the blades bronze-welded to the bracket shell, but later ones used a special cast bracket with sleeves to receive the blades.
First introduced in 1983 as a "Bernard Thevenet" branded CIZERON, the model emerged a year or so later in the colours of Cycles Delcroix of St Amand les Eaux near Valanciennes in northern France.