The Lotus Seven Series IV
press materials and story as told by John Robinson
Lotus Seven Series IV Press Kit, 11 March 1970
The designer for the Series IV was a gentleman called David Baldwin. Alan Barrett made the moulds for the bodywork and then the bodywork itself, and I was involved with the mechanical side. Arch Motors made the chassis for the Lotus Seven Series IV.
Note: Sometime after publishing this article from John Robinson, I was in contact with David Baldwin. He advised that Peter Lucas was the designer of the Lotus Seven Series IV. Peter Lucas was also responsible for designing the extra triangulation required for the Series 3 Twin-Cam SS cars.
We worked in a large lock-up garage across the road from the main factory and we started with a Series 3 in the first place.
With known problems with the suspension on the Series 3, we first looked at the front suspension, as the bump steer was very bad i.e. 3/4″ toe out on full droop of the suspension, going to 1″ toe-in on full bump. This was almost all removed by raising the rack and pinion up by around 2″ and at the ball joint end replacing the joints with a racing type adjustable joint.
The rear suspension was a different matter and I can remember quite clearly the day I re-learned how to weld. On the Series 3 there was an ‘A’ frame that located the axle, this David had re-designed for the Series 4 to the 2-piece system i.e. a small “A” and a separate link. I made up the required jig for these frames and proceeded to make the frames. I went and fitted them on the car and checked that the suspension worked, and called David to check that it was installed how he had designed it. He promptly jumped into the car and took the car to the test track with me as passenger, where he proceeded to drive the car far quicker than I had ever been before.
When we finally arrived back at the workshop with me still shaking at the thought of the welds on the suspension that I had made. I rang across to the fabrication workshop where I made immediate plans for later that day to learn how to weld properly, as that was the first time I had ever made anything that complicated!
Other modifications were tried on the Series 3 and my wife and I would go off with the car most nights and drive for 100 miles to test the mods. My aunt in Bournemouth (Dorset, U.K.) was not surprised to see us drop in for a cup of tea before returning home, some 300 miles round trip on a Sunday.
As mentioned previously, the fabrication of the Series 4 took about 2 years to complete and I was involved in setting up the production in the main factory. This was when I was approached by Tim Goss.John Robinson on the Series IV production line with a Twin Cam, photos courtesy Lotus Press Office, Stewart White, and Eastern Daily Press.