SM pricing: the report by insurer Rosset and Paul Magès's response (February 1971)

In this document

The insurer's test and report

The Groupement Technique des Compagnies d'Assurances (Technical Group of Insurance Companies) had a Citroën SM loaned "from Friday 27 to Monday 30 November 1970", with a familiarisation session "during a circuit at the Bois de Boulogne on the morning of the 27th" devoted mainly to the power steering p. 135. The report is signed by V. Rosset, director of the company Le Secours, a "former polytechnicien" p. 133-134.

Rosset acknowledges the handling and road holding, but expresses reservations: the steering, "of a totally different type from that usually encountered", could become "a danger element" in the event of a "reflex movement" p. 135; high speeds "surprise users" p. 136; finally, regarding comfort, "the engine is noisy", "the quality of the bodywork seems average (door not closing on the loaned vehicle)" and "the suspension […] filters vibrations from small bumps poorly", unlike the "D models" p. 136.

Internal transmission at Citroën

Mr. Pestel's note of 9 February 1971 ("N/Ref: D.3. P/MB") forwards the report to Mr. Grosseau, judging some criticisms "excessive" but believing that a response is necessary "in consideration of the quality and audience" of their authors p. 133. Grosseau replies on 15 February, attaching "Monsieur Magès's comments" and proposing to transmit them to Rosset accompanied by BEA reports no. 669 and 859 p. 137, 141-142.

Paul Magès's response (Design Office note no. 1166, 15 February 1971)

Magès acknowledges the criticism regarding the suspension: "the stiffness and inertia of the tyres, necessary to obtain road holding […] at over 200 km/h, are the cause of shocks and vibrations […] if one designs it with the primary concern of safety" p. 137-138.

He defends speed as a "safety element" when used correctly, citing the GS as an example of a high safety coefficient p. 137. He recalls having "studied and tested the steering applied to the SM for 12 years" and invokes the "on-axis" pivot, present "for 16 years on the DS" and used again on the GS p. 138, 144. Finally, he compares the reception of the SM's steering to that reserved, in 1955, for the power braking of the DS, which had also "frightened" before drivers adapted p. 139, 145.

Context

The SM, a high-end coupé launched by Citroën in 1970 (Maserati engine, variable-ratio DIRAVI steering), embodied a "sports" car accepted as such, unlike the DS, a more consensual grand tourer. The car pricing groups mentioned by Rosset (13, 14, 15) refer to the French insurance system of the time, classifying vehicles by power/performance categories.

Archivist's perspective

This file illustrates, through an ordinary administrative exchange (insurance, pricing), the role of technical defender that Magès adopts for his inventions: he does not deny the observed defects — suspension and noise — but justifies them through deliberate safety choices, relying on the history of the DS and on previous internal reports (BEA no. 669 and 859).

It seems revealing that Magès uses, to reassure an insurer, the same arguments as those already developed fifteen years earlier for the DS p. 139, 145: technical novelty destabilises before it convinces. This document usefully complements the older reflections on suspension and steering found in Note of 11 September 1959: hydraulic or pneumatic suspension and Bougeard patent and in the test report of 2 to 5 April 1962, which already addressed anti-roll and power steering on the DS.