Lea-Francis Models for the 1920/1921 Season

5 h.p. Lea-Francis 1920

Plated parts have been avoided and every other consideration shown for the all-weather rider on the new 5 h.p. Lea-Francis.

5 h.p. Lea-Francis 1920

Valve side of new 5 h.p. Lea-Francis power unit, showing the new three-speed gearbox with enclosed selector mechanism.

The 1920 Olympia Show.

Lea-Francis. (Stand 58.)

  • 5 h.p.; 64x92 mm. (592 c.c.); twin-cylinder four-stroke; overhead inlet valves; hand pump lubrication; Amac carburetter; Lucas chain-driven Magdyno; three-speed constant mesh type gear; chain drive; 26x2½ in. tyres.

Lea and Francis, Ltd., Lower Ford Street, Coventry.

The Lea-Francis needs no introduction; for many years it has been regarded by many as one of the highest class machines on the road, albeit one of the most silent. Even at a first glance the machine looks most serviceable and workmanlike - in fact, it in many ways reminds one of car practice, so thoroughly has the detail been studied. The M.A.G. engine is chiefly interesting because the inlet valves, together with their rocking levers, are enclosed, while the exhaust valves have their stems and springs exposed. From the exhaust ports gas is led through flexible pipes to a very substantial silencer rigidly bolted below the frame, and of considerable size. On the 5 h.p. machines power for electric light is supplied by a Magdyno placed in front of the engine, and efficiently guarded from mud by a curiously shaped coverplate, which also acts as an additional protection for the rider's feet.

The 3½ h.p. machines are not provided with this fitting, but the magneto is placed behind the engine. As am example of the detail work, it may be mentioned that the high-tension wires are carried through in steel tubes on their way to the plugs. The dry plate clutch of the 5 h.p. model is on the crankshaft and in a substantial aluminium case, which encloses also the chain drive to the countershaft, and an inspection cover, very similar to the one on the contact-maker of the magneto, allows the tension of the chain to be judged. On both models the gear box is of very robust proportions, and the oil filler on the 5 h.p. three-speed model is of exceptional size. On the 3 ½ h.p. 64x77 mm. model, the clutch is on the countershaft, and the gear box is housed in a circular lug which forms the bottom bracket, but in the new 5 h.p. machine an aluminium box is mounted on extensions of the engine cradles.

Olympia Show, 1920
The Motor Cycle, December 2nd, 1920. Page 701