The model was the successor to the ageing twin cylinderCB360 and the highly regarded, but expensive for the 400 cc class,four-cylinderCB400F. The CB400T has two fewer cylinders than its CB400F predecessor and although the press was initially skeptical of it, reviews stated that it was a worthwhile successor and more than capable of competing with contemporary rivals. Its overhead camshaft 395 cc (24.1 cu in) air-cooledparallel-twin had been completely redesigned, with a chain drive that operated three valves per cylinder, two for inlet and one for exhaust. It differs from rival manufacturers 400 cc twin-cylinder models because it has a 360° crank layout similar to many traditional British parallel twins instead of the more common 180° crank layout. Counter-rotating balance-shafts help to reduce unwanted vibrations caused by the 360° crank layout. Honda fitted these models with capacitor discharge ignition instead of the points system found on its predecessors, that required frequent maintenance. It uses a five-speed transmission with a chain final drive. Fuelling is provided by twin Keihincarburettors. A steel diamond cradle type frame uses the engine as a stressed member to reduce mass and increase ground clearance.
The CB400T Dream was introduced in 1977. It has alloy and steel compound Comstar wheels. Fuelling is provided by 32 mm Keihin carburettors. Braking is provided by a single hydraulic front disc and an expanding rear drum. The Dream was also available in a 250 cc (15 cu in) CB250T version to comply with the UK learner regulations at the time. Period reviews stated the bike was a mid-range tourer with rider comfort being considered one of its best attributes.
In the United States, the CB400T was known as the "Hawk" (stylised as "HaWk"). They were advertised under the slogan "Fly the Hawk – motorcycling will never be the same". The CB400T was marketed alongside the mechanically similar, more cruiser-inspired Honda CM400. It was launched in 1978 in three different variants, the CB400TI Hawk I, CB400TII Hawk II and CB400A Hawk Hondamatic.
CB400TI Hawk I
The “budget” model of the Hawk line up. It has front and rear drum brakes and spoked wheels with chrome rims. It is kick start only and the only instrument is a speedometer. It also has a slightly different and larger capacity fuel tank than the other two models. Due to the removal of certain components the Hawk I is actually 10 kg lighter than the more premium Hawk II.
CB400TII Hawk II
The "sport" model in the line up and more similar to the UK spec Dream. It has a single front disc brake with aluminum wheels. The instruments include a tachometer as well as a speedometer. Electric start supplements the kick start.
CB400A Hawk Hondamatic
The CB400A has a two-speed semi-automatic transmission.:42 It has a torque converter and two forward gears (high and low) that have to be manually selected by the rider. There is a gear position indicator in lieu of a tachometer in the instrument binnacle. A parking brake replaced the clutch lever. This model has 28mm Keihin carburettors which lower the peak power in exchange for low-down response.
In 1980, Honda only offered one model, designated as the Hawk, now simply designated CB400T. The CM400E took over the role of the cheaper Hawk I. It is similar to the European CB400NA. It has the same European styling and six-speed manual gearbox, although the pegs, footrest and gear lever are in the same position as the earlier Hawk variants. The bike became electric start only. Smaller 30 mm Keihin CV carburettors with accelerator pumps were fitted to comply with US emissions controls. The 1981 model is similar to the European CB400NB and has a dual piston front brake caliper, plastic front fender and a different tank shape.
Although the Dream was only on sale in the UK for six months, its successor, the Super Dream, was on sale for eight years. The engine and chassis underpinned various other models until the early 1990s, culminating with the CB450DX (1989-1992).
The Hawk and CM range continued as the CB450 Hawk, later CB450SC Nighthawk and CM450 models.