Sir,

Author

admin

I have studied Capt. J. S. Moon’s brilliant article with considerable care and interest. Granted his three fundamental requirements, I am, with one exception, in complete agreement with the details of his proposed design, and I think such a car as he outlines should be extremely attractive and not outrageously expensive.

The detail on which I disagree with him is the practicability of unified bodychassis construction for this style of car. The Citroen and Amilear roadsters seem to me to present two successful examples of low-built open cars with adequate doors and unified construction.

But where I really diverge from Capt. Moon is over the desirability of trying to make the car suitable for both fast road work and for trials, even of the “not too fearsome ” variety.

This compromise lands him in several difficulties. First, he is compelled to specify a rather large and expensive 5-speed gearbox, in order to have a low enough bottom gear. The second difficulty he does not touch on. To get the ” good ” ground clearance he requires for trials, he will have to increase the height of his centre of gravity, on which he rightly lays great emphasis, and to sacrifice either minimum frontal area or his ” kitchen-chair ” seating position.

Thirdly, for adhesion in mud, he will have to carry a large proportion of his weight on the rear wheels, a distribution which is undesirable for fast road travel.

Lastly, he is tied to rear-wheel drive and a transmission which obtrudes on the driving compartment. Even though he banishes the gearbox to the rear axle and bends the propeller-shaft under the front seat, if his floor boards are to be the lowest part of the car, his front universal and the front end of the propeller-shaft must stick above floor-level by half the diameter of the clutch housing at exactly the point where the third passenger wants to put his feet. This detracts considerably from one of the most attractive features of the car— reasonable comfort for three. My solution is .to make the car a pure road, machine, like the vast majority of classic sports cars, and to adopt front drive and unified construction. (With the disappearance of the propeller-shaft, the backbone chassis becomes an embarrassment.) Then all these awkward compromises vanish and the whole design becomes simpler, lighter and cheaper. I am, Yours, etc.,

C. W. S. MARRIS (Sqd. Ldr.).

R.A.F.