William Lyons was not content to merely build bodies on other people's chassis.  This constrained his creative desires and equally restricted him to products which were stolid rather than sporting.  If Lyons and Walmsley were to throw off these shackles, they needed to create their own chassis to suit their ends.  However, the industry was littered with failures and Lyons determined that a cautious approach was necessary. Consequently, he arranged for the Standard Motor Company to build a chassis to Swallow's design but fitted with Standard engines.  Meanwhile Lyons, the shrewd publicist, had set the scene.  'WAIT! THE "SS" IS COMING,' stated an advertisement in July 1931. '2 New Coupes of Surpassing Beauty. SS is the new name of a new car that's going to thrill the hearts of the motoring public and the trade alike. It's something utterly new … different … better!'  Thus announced, the SS I and SS II Coupes were duly presented at the 1931 London Motor Show, and sensation they certainly caused. The body was ultra low and the bonnet outrageously long. It had, stated the press, the £1,000 look, yet was priced at a very modest £310, highlighting Lyons' unique ability to offer remarkable value for money. 

Lyons was almost obsessive about making his cars as low as possible. By moving the engine further back in the chassis than was normal practice and by mounting the road springs alongside, Lyons was able to achieve this long, low, sporting appearance.  The SS II, which appeared alongside and was inevitably over-shadowed by the SS I, was simply a smaller version based on the Standard Nine chassis. Basking in the reflected glory of its more flamboyant and larger sister, the SS II would be popular and sell well. Remarkably it cost only £5 more than Standard's own version.  Shortly after the announcement of the new SS models, the larger 2552cc 20 hp Standard engine could be specified and for 1933 a number of revisions were introduced to make the larger car a little more practical. Lengthening the wheelbase by seven inches and widening the track by two, allowed two passengers to be carried in the rear.

In July 1933 the SS I Tourer joined the Coupe, and apart from being the first open SS model, the significance of the Tourers was that they were the first to be entered in a serious competitive event.  A team of three Tourers was entered in the 1933 Alpine Trial in mainland Europe and the following year they enhanced the SS name very considerably, taking the team prize on this particularly tough event.  The little SS II was considerably improved in late 1933 when it was given its own purpose-designed chassis which gave a wheelbase more than a foot longer.  At the same time the front wings were altered to conform to the new style of the larger model. Also, following the form of the SS I, Saloon and Tourer models of the SS II were introduced.  For 1934 a new saloon was added to the line-up. Known as a four light (four windows) saloon, this model was rather less flamboyant and rather more practical - at least the rear seat passengers could now see out! 

William Walmsley, who did not share his partner's driving ambition and was losing interest in the venture, severed his connections in late 1934.  Lyons now turned his attention to improving the mechanical integrity of the cars. First he turned to Harry Weslake, a distinguished engineering consultant specialising in cylinder head design. Then he formed an Engineering Department and appointed a young William Heynes to be his Chief Engineer. Heynes was to play a major role with the company for the next 35 years.  The range was once more supplemented in 1935 with the addition of the SS I Airline Saloon.  This design was not a particular Lyons favourite but the shape was fashionable for the time and sold well. Yet another model joined the line-up in March of that year when the SS I Drophead Coupe was introduced.  In appearance it was very similar to the Coupe but now the whole hood folded away under a hinged cover on the luggage locker and resulted in a most pleasing appearance.  The fruits of Weslake and Heynes' work were shortly to be seen but, meanwhile, a very stylish sports car was introduced. Known as the SS 90 and powered by the 2.7 litre side-valve engine, the performance once again did not quite live up to the car's dramatic appearance. But all that was about to be changed.