THE GOOD OL' DAYS
The 1934 Cars — Page 2
Now and then during the years, the various American automobile manufacturers purchased some of the leading independently sprung foreign cars, road tested them thoroughly for good points and bad and laid them aside.
Telescopic shock absorber is new on several cars. The Hudson equipment illustrated is said to smooth the ride at high speeds and when the going is rough.
As the years passed, however, American automotive engineers gave more and more thought to independent springing, and experimental cars were built and tested. So much work has been done that for the last two or three years it has been obvious that it was only a question of time before some American manufacturers adopted the new construction. And now the thing has happened.
The automotive industry resembles a small town in that "everybody knows nearly everybody else." And it is about as difficult to keep a new development secret as it would be in a small town. Therefore, let no one think that just because some manufacturers have adopted independent wheels this year and others have not, that the latter have been caught napping. On the contrary, those manufacturers showing conventional springing either believe that the old system is better than the new — all things considered — or their development work has not yet been carried to the point where they are satisfied to release independent springing for production.
To briefly explain the advantages urged for independently sprung front wheels, it should first be noted that with
conventional springing the wheels are supported by the axle and that the springs are not only necessary for resiliency but are also used to hold the axle in position and to resist braking torque. Inasmuch as the wheels are rigidly linked together by both axle and tie rod, a disturbance in one wheel has its affect on the companion wheel. And it is because of this cooperation that we have shimmy and tramp. These difficulties have also been experienced in some independently sprung designs, but at least it appears that these troubles are not nearly so likely to occur.
Advocates of the new system point out that with conventional springing, front springs must be stiffer than would otherwise be necessary in order to hold the axle in correct position under the various front end stresses, whereas with independent springing, all the spring has to do is cushion the car while the wheels are maintained in their correct positions by husky drop forgings. In consequence, the spring may be made as soft as possible for an ideal ride.
Also, inasmuch as there is no limitation on softness, the front springs may be so selected that they will not synchronize with the rears to aggravate pitching. With conventional springs, upward axle movement is limited to 2-1/2 to 3 inches before it hits the frame whereas upward wheel motion may be twice as great with independently sprung wheels.
Pitching in conventional cars is due to the fact that when the front wheels hit a bump the stiff springs kick the front of the car upward and this jolt depresses the rear considerably because of the softer rear springs. The use of much softer front springs causes very much less jolting to the front and correspondingly less depression to the rear — hence reduced pitching.
The writer has driven only one of the new cars with independent front wheel springing, the Oldsmobile Eight. To many readers, it may seem strange that all the other cars were unavailable. As a matter of fact, there was a Buick ready for the writer when he visited the factory but the roads were too slippery that day to permit a worth while test. In another case, road testing had been completed and the test cars had been torn down, while others had test cars scattered around the country too far away to be reached.
The ride in the Oldsmobile was a real thrill. First of all, the writer, sitting in the back seat, was driven over various roads ranging from smooth concrete, to rough concrete, to smooth gravel, to dirt roads full of ruts and deep pot holes. On all these roads, pitching of the car was almost entirely absent, which means that the well-known and disagreeable stomach shake was eliminated. Pitching, in a conventional car, occurs on all but the smoothest of roads and it is mainly because of pitching that so many people object to riding on the rear seat.
In place of pitching, this Oldsmobile had a gentle and wholly comfortable up and down motion. The dirt road with ruts and pot holes was rough enough so that at a mile a minute the rear axle hit bottom frequently and yet the writer never left the seat nor at any time could the ride be called uncomfortable.
Later on, the writer took the wheel and went over the same road at 40 m.p.h. with the steering wheel rim lightly pinched between the thumb and fore-finger of the right hand. So far as road reaction in the steering wheel was concerned the car might just as well have been rolling over a concrete boulevard.
Objections which are offered to independently sprung front wheels include increased front tire wear due to the fact that in some cases the tread varies according to spring compression, causing cross-scuffing. In addition, tire wear is increased because the wheels slant outward on turns. This condition has caused the use of special tread tires with more rubber along the edge and a grooved tread design with very little non-skid effect designed to reduce tire screech on turns. Harder steering on turns is another objection. The faults listed in this paragraph do not necessarily apply to all designs, and how serious they are remains to be seen. It is too early to say whether these shortcomings are really important or not.
Streamlining...De Soto is a striking example of the trend, with streamlining carried out from built-in headlamps to shrouded rear wheel.
The De Soto Six and the three Chrysler Eights are fully streamlined. At first glance these cars will look strange to most people but the writer finds that after you have looked at them for two or three days you become accustomed to them, and sooner or later you begin to admire them. Finally you are quite likely to come around to the viewpoint that these cars look right and that conventional cars look strange. The writer, for one, believes that these cars will be a great hit.
During the past several years, Chrysler engineers have done a tremendous amount of research on streamlined cars. About 50 wooden models were built and tested in the wind tunnel, and the new De Soto and Chrysler contours are the final development over these years.