The ex-works, Sir Jack Brabham, Aintree '200', Levin, Lakeside, and Sandown Park-winning
1961 Cooper Climax 1.5-2.5-liter T55 'Slimline' Formula 1 & Tasman Racing Single-Seater
Chassis no. F1/10/61

This superb and historic 1.5-litre Formula 1 Grand Prix and 2.5/2.7-litre Tasman Series car marks the end of the late double-World Champion Jack (latterly Sir Jack) Brabham's race-winning career with the Cooper Car Company works team. It was in its heyday an intermediate design that introduced Cooper to the newly introduced 1.5-litre Formula 1, serving until the latest Coventry Climax V8 engines became available.


Having achieved back-to-back Drivers' World Championship titles in 1959 and 1960, the Cooper team suffered as the new 1.5-litre BRM and Coventry Climax Formula 1 engines were so badly delayed that they were forced to use Formula 2-derived Coventry Climax FPF 4-cylinder power plants. This state of affairs imposed a tremendous handicap on the British manufacturers, as Ferrari was ready with its V6-engined 'shark nose' cars, which dominated the 1961 season.


To compensate for the modest power, each of the British teams built smaller cars than ever before, even though the new Formula regulations imposed a minimum weight limit, higher than that of the preceding 2.5-litre class. The design team of Owen 'The Beard' Maddock, John Cooper, and Jack Brabham himself, scaled down the preceding 2.5-litre and the new 'Slimline' was created. Only two of these dedicated works team cars were built – chassis numbers 'F1/10/61' (offered here) and 'F1/11/61', campaigned by Sir Jack's celebrated team-mate, Bruce McLaren.

The reduced power and torque of the new engine permitted Cooper's engineers to slim down the original gearwheels and so pack six where once lived five. It worked well, and this helped the driver's balance the relatively narrow torque band, particularly when the track was wet. Upon the new T55's debut at the Aintree '200' race, the team did their best to keep the six-speed 'box secret, and in heavy rain, recounts Bruce McLaren, it greatly contributed to the 1-2 result with Jack Brabham winning in the car we offer, with Bruce close behind.


At Monaco, Jack Brabham drove this T55 'Slimline' in midfield before retiring with ignition trouble. For the Dutch Grand Prix, 'Black Jack' finished 6th and then 4th at Brands Hatch on 3rd June 1961. At the British Grand Prix in Aintree, Brabham finished 4th, again, in the wet... The next race was the German Grand Prix, for which a third T55-based chassis – the unique T58 – was readied, ending this particular T55's works career. In all, the T55 cars finished 13 times from 19 starts in the 1961 Formula 1 season, the highlight of which must be Jack Brabham's victory first time out at Aintree in the extraordinary car offered here.

Sir Jack then took the car to New Zealand and Australia in early 1962, where it was campaigned in the Tasman Series, up-rated with 2.7 and 2.5-litre Climax FPF engines to suit. At Longford, Tasmania, Sir Jack finished 2nd in this car, narrowly beaten by John Surtees' similar 2.7-litre T53. Both were clocked at 171mph on the narrow public roads circuit!

The T55 was then sold to Tasmanian John Youl and campaigned though 1964. Since then it has been preserved, passing to various private collections, including that of Hollywood movie director, David Cronenberg, who has raced it successfully in various historic events.

As 'F1/10/61' was last raced in period in the Tasman Series, it has a 2.5-litre Coventry Climax engine fitted. The chassis was also updated with a higher rollover bar above the headrest, all clearly visible in the photographs taken prior to restoration, which was undertaken in 2014 by the well-known Swiss marque specialist Urban Fässler of Hinwil, now sadly deceased. As the vendors never intended to drive the Cooper, the restoration was undertaken to the highest standards but for static display only; indeed, the car has not been started or driven since acquisition.

As presented, the chassis looks the same as when it was raced by Sir Jack Brabham in the 1961 Formula 1 season (with the low rollover bar). The rolling chassis has been totally restored, as have the interior and electrics. The engine and gearbox have only been cosmetically refreshed to match the rest of restoration, and it should be noted that the old (cosmetically refreshed) aluminium fuel tanks are still present. Should the next owner wish to drive the Cooper competitively, FIA-specification bladder/foam inner tanks will have to be installed while all safety devices (fire extinguishing, seatbelts, rollover bar, etc) will likewise need to be updated to FIA specification. In addition, the engine and gearbox will need to be checked and overhauled, the wheels crack-tested, the tyres replaced, and the suspension set up for track use.

One of the most original early 1960s Formula 1 Cooper-Climaxes around - with numerous wins in Europe and its Tasman history at the hands of three-time World Champion, Jack Brabham - this is a very special Cooper indeed.