Automatic transmissions may seem somewhat unnecessary on motor cycles, but they are very popular in the United States and, as theirs is such a large market, it dictates that more should be made. The Honda 400 Auto is unique in that it is the first of the new-generation autos as a middleweight roadster rather than superbike, like the 1000cc Convert Guzzi and 750 Hondamatic.

The 400 is the CB400 Dream and, like the manual version, is a four-stroke, twin-cylinder machine. The Auto's engine differs in tune from the manual and has 3obhp at 8ooorpm compared to 43bhp at o,5oorpm. Torque is down just a little to 20.251b ft at 6000, which is 2ooorpm lower down the rev range than its sister bike and much more useful for its semi-automatic gearbox which has just two gears. The modifications are by way of smaller carburettors, smaller ports and milder camshaft. The three-valves per-cylinder (two inlet, one exhaust) twin with chain-driven contra-rotating balance shafts in auto guise is a very smooth and well-mannered machine indeed, even if performance is riot a strong point.

The bike's gearbox is not truly automatic in the car sense, being a two speed unit with torque converter

 and manual change. First gear is for up to 5omph, while second will take the machine to its top speed of o,5mph.

Riding the 400 requires a new technique. The bike will only start if the gear selector is in neutral and the gearchange order is neutral at the bottom, with the two gears 'up', second above first. Should you forget to take the bike out of gear and put the side stand down, a failsafe switch will cut-out the ignition, thus preventing the bike from taking off without the rider.

The bike works remarkably well if just left in the higher of its two ratios and will pull away, albeit fairly slowly, from second gear. As can be expected, even using both gears, acceleration is not startling, with a standing start quarter mile time of 17.2 sees. Fuel consumption is good, however, and can average out at just on 6ompg.