FRONT WHEEL DRIVE AND TORSIONAL SUSPENSION
EXTENSIVE EXPERIENCE OF THE CITROEN TWELVE
FRONT wheel drive and torsional suspension—features of specification of interest to all enthusiasts and students of design. It was to make better acquaintance with these features that we recently put a Citroen Twelve through its paces under a wide variety of conditions and over a quite extensive mileage. The Citroen Twelve saloon is certainly not a sports-car, but it is basically the same chassis as that used for the open twoseater Twelve and the higher performance Light Fifteen. It is a very interesting chassis indeed, for Citroen broke completely away from utility car design, after success since the early post-war years with the 7.5, 11.4 and 12 h.p. cars, and introduced, a few years ago, the existing torsionally suspended, front wheel drive chassis ; one of the most successful cars of unorthodox layout ever marketed. One’s very early impression of the Citroen Twelve is that of being behind the wheel of a much bigger and more expensive car. For this the torsional suspension must undoubtedly take credit, for the car rides with rocklike solidity over all kinds of road surfaces, displaying hardly a trace of pitching or side sway. Indeed, no roll occurs even under really quick cornering, and the only time the suspension displays any trace of suppleness is after taking hump-back bridges at speed, although, from the degree of genuine comfort it affords, one would expect, and certainly excuse, some trace of flex
ibility. The special all-steel frameless construction must also contribute very materially to this steady riding of the Citroen and its rigidity does at times convey a slightly ” dead” feel to the manner of riding.
It is not only luxurious running that suggests a larger car. The Citroen is a willing performer, as we soon discovered in hustling from the works at Slough to Brooklands, a journey for which we had craved a sports-car, until we found how easily the Citroen gets through traffic and settles down to an effortless cruising gait of 60 m.p.h. on derestricted roads. On second gear of the three-speed box excessive valve-bounce limits the maximum to 40 m.p.h., but up to that speed very brisk acceleration is commanded. The most interesting feature of the Citroen is the front-drive layout. It makes a very considerable difference to control and has only very minor disadvantages to off-set this commendable characteristic. The Citroen Twelve is one of the most controllable cars we know. On wet roads, slimy with weeks of rainless weather, it will naturally slide if encouraged, but so effectively does it respond to the steering that after a little experience of its abilities in this direction one can literally sling it about on greasy roads without restraint. Here it is that the front drive is so valuable. Even on the over-run the car is very very stable, but if one has any doubts about where it is going one has only to turn on the power and the front wheels never fail to pull the car in the direction in which they are pointing. Particularly was this evident on London streets notorious for their slippery surfaces. Under conditions when the front wheels would spin furiously under acceleration, we certainly experienced. loss of front wheel adhesion on the over-run on corners, but, on accelerating, directionability was at once restored. In consequence, one is able to do most remarkable things with the f.w.d. Citroen, on greasy roads and fast open bends alike. Round long lower-speed curves, there was a rather less pronounced feeling of stability, difficult to define, but always was the car under control. In cornering there is hardly any trace of severe roll, and the car goes round as on rails, with a fair amount of protest from the Michelin ” Stop ” Real Low-Pressure tyres, chiefly from those on the front wheels. What of the disadvantages of this front wheel drive We have been warned of increased noise from having the gearbox and transmission under the bonnet instead of under the floor. In the case of the Citroen, there was a certain drumming or vibration on the over-run at times, but otherwise the transmission gave no clue to its whereabouts, and the gears were almost
silent. We had heard that f.w.d. can adversely affect steering and cornering qualities. So far as the latter consideration is concerned, we have already commented on the effectiveness of the front drive in rendering the car stable under sticky going.
In the matter of steering, certainly under load the steering became stiffer than on the over-run, tending to vary from moderately light to fairly heavy, but it remained, even on the drive, smooth in action and was moderately high-geared so that undue work at the large diameter wheel was not necessary. There was sufficient castor action at all times and hardly a trace of return moment came back through the wheel, nor was there any column vibration. The lock is quite adequate. By the time we had arrived at Brooklands we began to enjoy the sense of big.. car comfort afforded by the Citroen and were impressed by its general solid construction. The interior finish is in leather, with carpeted rear compartment, and separate and adjustable bucket front seats of generous dimensions, and there is a sliding roof. Reverting for a moment to the front drive, it is possible to accommodate three persons on the front seats in view of the absence of a normal gear
lever. The only other point likely to be raised by those cautious of unorthodox layouts concerns adhesion on hills, and later in the test we tried some trials gradients with this in mind, with entirely favourable results, as detailed below. Outwardly, there is something very pleasing about the sleek clean lines of the aerodynamic saloon body, with its flush fitting bonnet with side inspection doors, inclined radiator grille, flowing wings, and artillery steel wheels. Incidentally, the floor is at a very low level so that, although no running boards are fitted, entry and egress are particularly pleasant to accomplish. On Brooklands the Citroen rode in a dead steady manner, even to feeling a trifle “dead,” and in consequence felt
essentially stable. Lots of fast lappery did not appear to disturb it, and although no thermometer is fitted, the oil gauge showed a consistent 25 to 80 lb. per square inch at speed, as on the road—we dislike these modern oil gauges with spidery needles and dials as part of a main dial and often wonder whether they read true ; but then they are common on modern utility cars and Americans. The lap came out at 60.5 m.p.h. and the flying half-mile at 65 m.p.h., at which speed the speedometer indicated 68 m.p.h.
The Citroen is thus not a fast car, but one judges it not so much by its 65 m.p.h. maximum as by its complete lack of fuss at all speeds on the road. It is especially complaisant at 40 m.p.h., but will cruise very happily at 55 to 60 m.p.h. The engine makes some carburetter noise when accelerating and there were a few body noises, otherwise the car does its work quite effortlessly, and covers the ground very fast by reason of its good cornering qualities. Acceleration is of the order of standstill to 50 m.p.h. in 21 sees., and on the road the urge on the lower gears is distinctly usable. The gear-lever projects as a down-dropped fairly slender lever, from the centre of the facia, rather over to the near side. One very soon becomes accustomed to the action and thereafter only very occasionally does one feel a desire for the conventional sort of gearshift. Certainly on the car tried the lever moved stiffly, but with steady, as distinct from wild, movements the changes went through quite well, and reasonably rapidly, the synchro-mesh being fully usable, with no time lag. Bottom could always be located, albeit with a crunch
under brutal engagement. Only once or twice did the driver become confused as to the sequence of lever movements. There is a remote possibility that a child, or a careless adult passenger, might get a finger caught in the dashboard gate— personally, we remembered to warn those privileged to sit on our left. The clutch was extremely smooth and progressive, required only moderate pressure to disengage, and felt positive.
The handlever is in the form of a cranked lever protruding by the driver’s left leg. To hold the car in traffic it is pulled outwards and. to lock it one turns the handle to the right. It was a trifle inconvenient to locate and rather vague at times in respect of locking on, but it functioned smoothly, one gradually became acclimatised, and, in company with the dashboard gear-shift, it permits of great spaciousness in the trout compartment. After having gained familiarity with the Citroen we left it in the drive over night, before starting off to meet the Antwerp boat at Harwich at 6.30 am. next morning. The engine commenced at once, and pulled away well, with the choke fully extended for the first mile or so. This night run fully endorsed our already high opinion of the car’s ability to maintain a high cruising speed and of its extreme stability. The roads were awash and treacherous after the drought, but any slides we experienced were Instantly brought under control and were occasioned solely on account of an exuberance of enthusiasm. Taking a mileage reading at the grim hour of 4.50 a.m., while still in the Mile End Road, we covered 50.3 miles in the following sixty
minutes. Even granting the absence of traffic, this indicates that the Citroen can get about very rapidly from place to place, and, moreover, in silence, riding smoothly and steadily. The brakes are entirely adequate, and slow the car steadily with no fuss, or detrimental effect on stability. For rapid stops a fairly heavy pressure was required and the action is a trifle spongy, but no loss of braking power was noticeable at the conclusion of the test, which extended over 520 miles. The lamps were good without being ultra-powerful, and the dimmer, operated by a lever on the steering column extension, very convenient to use and effective. This extension also carries the horn button (we prefer it on the wheel centre) and the direction indicator switch, well placed save that one was apt to knock it accidentally. The arms are of self-cancelling type operated from the steering wheel movement and at times tended to cancel rather early. The facia carries, from left to right, a usefully large cubby-hole with no lid, swivelling ash-tray beneath, gear-gate, combined fuel-gauge, oil-gauge and ammeter, speedometer with inset clock, and combined lighting and ignition switch, the
latter with removable key. The concealed dashboard illumination was effective, but the left hand large dial was permanently lit, whether intentionally or because of partial failure of the dashlight switch we do not profess to know. It in no way resulted in dazzle, but, suffering in the early a.m. from liver, we would have given much to be able to douse it. There are twin anti-dazzle visors and effective twin screen-wipers, and the interior illumination is excellent, controlled by a switch low down and within reach of the driver, or a passenger in the off side of the rear seat. The screen will open, by operation of a central knob, and was not entirely leakproof in a downpour. The
sliding roof worked well. The screen pillars are rather heavy, but visibility is excellent, as the near-side lamp is visible. The high-set headlamps are brightly plated and in consequence it is easily possible to ascertain whether the side lamps are burning, quite apart from their indicator glasses, a reassuring point to those drivers who put out—as they should–their headlamps on entering well-lit streets. On the journey away from Harwich we appreciated the accommodation afforded by the rear luggage-locker, on the lid of which the spare wheel is carried within a metal case, and the spaciousness of the rear seat, which will comfortably accommodate three persons. Small ash-trays, inscribed with a tiny chevron, are provided in the rear compartment. The doors and luggage-locker are lockable and the front doors have elastictopped pockets. A good point is the provision of jacking pads on the axles. The Citroen ” Mono shell” all-steel coachwork must provide very valuable protection in the case of a serious accident. A useful driving mirror and rear blind are provided.
The dip-stick, distributor and plugs are accessible on the near side and the o.h. valves are enclosed in a neat, polished valve cover with oil-filler in the lid. The radiator filler cap is under the bonnet and the battery is accessibly placed on the engine side of the facia, while spare brake fluid and electrical fuses could hardly be more easily get-at-able. Over rough going the whole car retains its feeling of solidity, although there is some lamp movement and the bonnet top would ripple under clutch engagement in bottom gear. Turning to the specification, the fourcylinder 72 x 100 mm. 1,628 c.c. engine is rated at 12.8 h.p. It has a balanced three-bearing crankshaft, detachable cylinder barrels, alloy four-ring pistons, and push-rod actuated o.h. valves. The larger engine of 78 X100 mm. (1,911 c.c.), rated at 15.08 h.p., is obtainable in the
same chassis. A Solex carburetter is used and cooling is by pump and fan. Coil ignition has automatic advance and retard. The drive passes via a single dry plate clutch to the unit three-speed and reverse gearbox, differential and bevel front wheel drive. Front suspension is by torsion bars and parallelogram linkage and rear suspension by similar torsion
bars. Lockheed hydraulic four-wheel brakes are used. The pressed steel wheels Carry 140 x 40 mm. Michelin Real Low-Pressure covers. The gear ratios are 4.9, 8.3 and 14.8 to
1, reverse 19.7 to 1. Wheelbase 9 ft. 61 in., track 4 ft. 41 in., turning circle 46 ft., weight 20i cwt. The fuel tank holds 9 gallons, giving a range of 180 miles approximately at a consumption of around 20 m.p.g. In conclusion, the Citroen Twelve is a solid car possessing some remarkably interesting and practical technical features, and offering quite rapid transport with a high degree of comfort and convenience. It upholds the reputation enjoyed by Continental productions for safe sports-like road-holding, yet displays no flimsiness in its construction or manner of riding. On Allington hill, wet and very sticky, wheel spin defeated us only at the summit, and Coldharbour was a first and second gear ascent with full load, while Beechy Lees would have been a fast climb had not a gear jumped out. Our experiences of these and other Rent trials hill confirmed the belief that, correctly applied, f.w.d. is no bar to hill storming. Priced at £238, taxed at 49 15s. Od., and with a twelve months’ guarantee, the Citroen is amongst the
most interesting of Twelves. Full particulars may be had from Citroen Cars, Ltd., Trading Estate, Slough, Bucks.