Tests of the 2 CV with hydrostatic transmission at Mont Ventoux (29 June 1960)
Handwritten performance records comparing a 2 CV equipped with a hydrostatic transmission to a support vehicle, during a first ascent of Mont Ventoux.
Understanding this document
In this document
The tests of 29 June 1960
Page 125 bears the header "Transmission H 2 CV" and the mention "29. Juin _ Ventoux" p. 125, repeated identically on page 126. Page 127 specifies the meaning of the event: "29 Juin 1960 — Le Ventoux [pour la] 1er fois avec Transmission Hydrostatique" p. 127, highlighting that this is a first ascent of the mountain for a vehicle equipped with this device.
Component mileages
The notes indicate a "1000 Km. démarage" then, on a date noted "26 juin" p. 125 or "30 juin" p. 126 depending on the page: "5200 Km (pompes)" and "8000 Km (récepteur/récepteurs)" p. 125-126, reflecting a follow-up of the cumulative mileage of the hydraulic pumps and receivers.
Measured relative efficiencies
The same efficiency table appears on both pages:
| Route type | Relative efficiency | Distance | Page |
|---|---|---|---|
| Hard mountain | 0.98 | 200 Km | p. 125-126 |
| Average | 0.93 | 300 Km | p. 125-126 |
| Flat | 0.85 | 400 Km | p. 125-126 |
| Overall | 0.9 | 900 Km | p. 125-126 |
Page 126 adds a comparison "Par rapport a 2 CV d'accompagnement (consommation)" p. 126, showing that a standard 2 CV control vehicle accompanied the test to compare consumption.
Other components mentioned
Page 126 lists, without usable numerical detail, several technical points: "Amortissement [fin] de course & 2", "Correcteur [hauteur] x 1", "Anti-roulis, 2 solutions, 6-7" and a comparison of suspensions ("Susp. Camion : 4", "2 CV (C) : 3", "V air : 5") p. 126. Ventilation and compressor are also mentioned at the end of pages 125 and 126, without further precision.
Context
Mont Ventoux, with its steep slopes and long climb, was at the time a classic test ground for proving engines, transmissions, and suspensions under severe conditions. The 2 CV, a Citroën model emblematic of mechanical simplicity, served here as an experimental base for a hydrostatic transmission, an alternative technology to the mechanical gearbox, then under development at Citroën in parallel with Paul Magès' work on hydropneumatic suspension.
Archivist's perspective
This piece documents, it seems, a landmark stage in the hydrostatic transmission tests: the first confrontation of the system with the demanding terrain of the Ventoux p. 127. The efficiency measurements by terrain type p. 125-126 testify to a methodical approach of comparison with a reference vehicle.
This document probably belongs to the same test campaign as the Record of mileages of test vehicles with Hydrostatic Transmission (1960-1973), which covers the year 1960, and finds a later echo in the Follow-up of endurance tests of the 2 CV A12 with hydrostatic transmission.
In the same folder
Magès' handwritten notes: "Presentation T.H. 50 CV" at the B.E.A. (15.9.64)
Comparative curves manual gearbox / H.T. on DS 100 HP (Prestrelle, February 1962)
Magès patent project (1958): automatic regulation for continuously variable transmission
Dating
29 June 1960
Document
3 pages
Source: « Scanner 18 août 2025 à 15.25.pdf », p. 125–127
Category
Archival note
p.125 photograph annotated "Transmission H 2 CV, 29 juin – Ventoux"; p.126 same efficiency figures; p.127 caption "29 Juin 1960 Le Ventoux pour la 1ère fois avec Transmission Hydrostatique"; summary p.164.