Frame is upswept over front and back axles to achieve lower centre of gravity. Underslung front and rear axles machined from solid billet (back axle to 3mm thickness). Front axle H-section. U- shape sub-frame carries the engine, clutch and gearbox and mounted on the chassis at three points. Alignment of front end of crankshaft is below the centre line of the rear axle; as such the line of crankshaft, the transmission and the propeller shaft slopes downwards towards front in order to keep centre of gravity as low as possible.

Chassis dimensions and weight of surviving cars vary indicating specificity in body fitting.
Wheelbase 8ft 9 in, Track 4ft 7in

Weight :
1921 Grand Prix de l’A.C.F. – 19.5 cwt
1922 IoM T.T.:
K Lee Guinnes – 21cwt 99lb
H.O.D. Segrave – 22cwt 31lb
J. Chassagne – 22cwt 10lb (2,474lb)
Engine weight dry 520lb.