STRENGTHENING THE CHASSIS FRAME

Evening Star, Issue 22271, 24 February 1936, Page 13

STRENGTHENING THE CHASSIS FRAME

The changes which have been made in the construction of chassis frames during recent years are due largely to complications brought about by new forms of engine suspension and other alterations such as independent springing, which have forced manufacturers to devote more attention to the framework of the car than might have been necessary if such innovations were lacking. The aim has ever been at procuring rigidity. To-day, because of faster speeds and the demand that deadweight should be reduced, the build of the frame is of great importance.

In a review of the trend of design, the ‘ Motor ’ refers to the circumstances which have arisen, and points out that, although engine suspension might not appear to be associated intimately with the robustness of the chassis, it has become an important factor, since the engine is no longer attached rjgidly to the chassis, and has ceased to serve as a valuable cross member which reinforced 'the frame work. More flexible springing and im dependent front springs have also brought problems in their train, with a result that cruciform bracing has become popular, but has the disadvantage that often a heavy “ x ” member adds considerably to the weight of the vehicle..

Some manufacturers have accordingly accepted the box type of main frame member, which offers much greater resistance to torsional strains than does the older sort. The box member, which is used in several of the 1936 productions, is virtually a rectangular tube with welded joints, and because of the great resistance which it offers to twisting, can be made of thinner metal than the normal side member. Solid-drawn steel tubes have been employed for the foundations of certain light sports models, and on other cars there are side members with a zig-zag of steel plate running the full length of the channel. Some Continental fac tories favour the “ centralised ” or “ backbone ” frame, whose title is selfexplanatory, and which is peculiarly suitable for cars having independent suspension of all four wheels.