Honda CB 750A Review
The idea behind the creation of the CB 750A was pretty simple. As good as the CB 750/4 was, it was still a large and heavy bike that took a degree of riding skill to get the best out of it. By removing the need to change gear, Honda thought that new riders, or those returning to riding, would be attracted to the ease of operation that an automatic CB 750 offered. As with the original CB 750, the 750A was aimed primarily at the lucrative American market. With automatic-equipped cars selling strongly in the US, Honda hoped an auto motorcycle would be just as popular, as well as being a more fuel efficient alternative to an automobile. The 'Hondamatic' equipped CB 750A was announced in 1975, and came hot on the heels of a similar system released by Moto Guzzi in the same year.
Also known as the '750 Hondamatic', the CB 750A wasn't an auto in the truest sense. Semi-automatic would be a more accurate description, as the gear changing still required use of a foot pedal (on the left-side) to shift from neutral to low and high gear. The torque converter mechanism was lifted directly from Honda's compact N600 car (Honda's version of the Mini Minor). In the N600, the Hondamatic had been fitted to an air-cooled 600cc twin cylinder engine, so its application to a 750cc four cylinder motorcycle engine was relatively simple. The CB 750A's engine was outwardly the same as other models, but featured a different crankshaft, primary drive chain, camshaft, lower compression pistons and smaller (24mm) carburettors. De-tuning the engine meant less top end power, but delivered the additional torque required at lower rpm to suit the Hondamatic transmission.
The actual Hondamatic system was essentially a torque converter, using oil pumped through a series of turbines to drive the gearbox mainshaft, and in turn the drive itself through through a three-way hydraulic valve to a pair of hydraulic clutches. Acceleration dictated the speed and torque multiplication. As the system was hydraulically-controlled, the engine lubrication oil was used to both power the hydraulic shifting and keep it cool. The finned aluminium torque converter was reasonably efficient at dissipating heat on its own, but the engine's air-cooling meant the "all-in-one" lubrication and transmission fluid was kept cool in all but extreme conditions. One feature specific to the motorcycle Hondamatic was an override feature on the torque convertor's outer stator turbine that prevented slipping on the hydraulically-operated clutches. Thus, shifts between and 'low' and 'drive' in either direction were always smooth, with no lurching. In addition to being easier to operate, the Hondamatic was also quieter than Honda's standard manual transmission.
Seen from the near side, the differences between the CB 750A and a manual CB 750 weren't immediately apparent. However, the differences were more obvious on the off side, where the large round housing for the torque converter - and absence of a kick start lever - were more obvious. With cruising in mind, the CB 750A also featured a larger fuel tank and reshaped rider/pillion seat that was more luxuriously padded, with a pillion grab rail at the rear. The side panels were reshaped to follow the lines of the seat. While based on the CB 750K, the debut-year CB 750A used parts lifted from other Honda models, like the 4-into-1 exhaust system and disc front brake from the CB 750F, and the DID aluminium wheels and chrome front mudguard from the first generation GL1500 Gold Wing.
Given the nature of the transmission, Honda considered that a park brake was necessary for the CB 750A. This worked by use of a pull-out knob on the near side of the fuel tank. With the brake pedal depressed, pulling out this knob locked the rear brake on. Pushing a button on the same lever while holding the pedal down released the rear brake. Safety features included a linkage to the side stand that engaged neutral when it was lowered, and a cut-out to prevent the bike being started in gear. As mentioned, the CB 750A was electric start, but a kick start lever was supplied, clipped underneath the seat, to be used if required.
As a visual aid to the rider, the right hand instrument pod featured large indicator lights for when the bike was in 'neutral', 'low' or 'drive' (high gear). This was further assisted by the left hand instrument pod that carried indicators on the speedometer of the recommended ratios for 'low' and 'drive' - 0 to 100kph and 100 to 170kph respectively. Although the speedometer went round to 120 mph (192 kph) road tests of the CB 750A when new only seemed to reach a top speed around the 90-100 mph (145-160 kph) mark.
So, for all its innovation and rider-friendly features, the CB 750A should have been a hit. Honda certainly thought so, figuring that Americans would snap up the auto 750 as an easy-to-operate and cheap-to-run alternative to four wheel commuters in the wake of the oil crisis of the early 1970s. A side-by-side test of the new CB 750A and a CB 750 F in Cycle World magazine (US) in late 1976 praised the 750A as being smooth and easy to ride, but questioned whether it would draw 'newbies' to motorcycling. They suggested the Hondamatic system may have been better applied to a smaller and lighter bike.
As it turned out, the Cycle World tester's doubts proved to be accurate. The CB 750A never really found the market Honda hoped for, for a number of reasons. Firstly, the idea of a clutchless motorcycle wasn't really seen as a viable alternative to a car, regardless of its advantages. Secondly, the system was applied to a bike that, at around 260 kg and with an 838mm seat height, was too large and heavy for first time riders. Thirdly, the bike wasn't overly fuel efficient, at least when compared to a 'manual' CB 750. And finally, existing riders actually liked manuals. Snicking through the gears was a feature most riders liked. Lose that and you lost part of the appeal of riding.
Despite not being the success they hoped for, Honda persisted with the CB 750A for two more years following the 1976 debut model. 1977 and 1978 models were identified by cosmetic changes only. The CB 750 'A1' from 1977 featured a 4-into-2 exhaust, two-tier seat and optional luggage panniers in an effort to recast the model as more of a tourer/cruiser. In 1978, the 750 A2 featured Honda's 'Comstar' cast alloy wheels. Colour scheme and minor detail changes also helped separate the A1 and A2 models. After 1978, Honda dropped the model from the CB 750 range, but applied the Hondamatic system to the smaller CB 400. In this application, the auto Honda endured for another three years.
Over the three year lifespan of the CB 750A, only around 8,000 examples were produced - a very low figure compared the numbers of CB 750 K and F models made during the same period. This has made the CB 750A a very rare item today. Consequently, it's on the radar for collectors of early Japanese bikes. With virtually all the CB 750As built going to the US, they're a rare sight anywhere else. While not a success, the CB 750A is by no means a bad bike. Acceleration is mild, but power delivery and gear changing is smooth. The bike rides and handles quite well, although the suspension is a little firm and the auto operation does take some getting used to. The quirkiness and rarity of this forgotten chapter in the CB 750 story would make it an interesting addition - and great talking point - in the collection of any fan of classic Japanese motorcycles.
Honda CB 750A - basic specs
Engine: 736cc SOHC four stroke four cylinder
Bore/Stroke: 61.0 x 63.0mm
Compression: 8.6:1
Transmission/Drive: 2 speed semi-automatic/chain drive
Fuel System: 4 x 24mm Keihin carbs
Cooling System: Air
Front Suspension: Telescopic forks
Rear Suspension: Swingarm with twin shocks
Front Brake: Disc
Rear Brake: Drum
Front Tyre: 3.50 - 19
Rear Tyre: 4.50 - 17
Wheelbase: 58 inch (1480mm)
Seat Height: 33 inch (82.5mm)
Weight: 565 lb (256kg)
Fuel Capacity: 19.3 ltr
