Advanced newcomers from Honda

Press, 23 February 1978, Page 11

Advanced newcomers from Honda

By

ROD DEW

Two new Honda models I certain to attract a great i deal of attention are scheI duled to arrive in New i Zealand later this year. I They are the remarkable | six-cylinder CBN of 1047 i cu. cm and the V-twin CXsoo—technically among th j most advanced fourstroke roadsters in the world. The water-cooled CXSOO is expected to be on sale in New Zealand in May. Also planned for release at the same time is the new CR2SOR moto-cross racer. However, this is intended only for limited distribution. It will be available to selected riders through Honda dealers involved in the sport. The mighty CBX is not j expected to make its I appearance on New Zea- | land roads until July. This i will coincide with the arri- , val of the completely reI modelled XL2SO fourI stroke trail bike. SIX IN LINE The transverse in-line I six is claimed to be the i fastest and most powerful 1 production roadster in the i world, although this is ceri tain to be disputed by I other manufacturers. The claimed maximum speed is t 225km/h, but this is of aca--1 demic interest only when i one is talking about a machine powered by an engine developing 105 b.h.p. For those who have long ! enjoyed the smooth power and mechanical excellence of the four-cylinder Hondas, the increase in the

number of cylinders will be something of a puzzle. It is, after ail, hardly likely that the full power of a machine bigger than the 750 s could ever be fully utilised. It seems that Honda, which led the field with

its 750 s for so long, has got caught up in the horsepower race. But even if this trend can be criticised, the excellence of the new Honda certainly cannot. If one did not know motor-cycle manufacturers better, one could be pur-

suaded to describe it as the ultimate machine. But nothing is surer that someone will come up with something even better—and more costly—before long. The Honda engine delivers its 105 b.h.p. at 9000 r.p.m. and boasts maximum

torque of B,skg/m at 8000 r.p.m. The adoption of a six-cylinder engine has allowed smaller cylinders to be used, resulting in a lower engine profile and bike height and light pistons. The light pistons, combined with a big bore of 64.5 mm and a short stroke of 53.4 mm. enable a high engine speed to be maintained without stress.

The piston speed at 10.000 r.p.m, is a safe 17.8 metres a second. With four valves a cylinder, the valve weight is also light and there is no danger of valve floating. Six in-line constant velocity carburettors feed the engine. The five-speed gearbox ratios are much closer than those of the GLIOOO and slightly closer than those used in the C 8750. The traditional chain drive is retained, which is a surprise in view of the trend towards the more expensve shaft drive. For a sports bike to be worthy of this description, it must be agile and nimble. This means that its wheelbase must be reasonably short. The CBX excels in this regard. At 149.5 cm, its wheelbase is considerably shorter than that of the GLIOOO and almost the same as the C 8750. DIAMOND FRAME Honda has preferred a diamond frame instead of the conventional double cradle. The diamond variety has no down tubes and the engine block be-

cames a part of the frame. This allows the front forks to be positioned close” to the engine, which is inclined 30deg forward to provide greater space behind the block and easy access to the carburettors. The six-cylinder engine : is wide but by inclining it I the manufacturers have I kept the block clear of the rider’s knees. The alternator and ignition unit are linked to the primary shaft instead of to both ends of the crankshaft as is the usual custom. This provides for a narrow crankcase width. It might come as a surprise to many riders to learn that the footrests are 6cm closer together than on the C 8750. The exhaust system is of the six-into-two variety. The ignition is fully transistorised. The engine is air-cooled but an oil cooler ensures that the correct lubrication temperatur° is maintained. Tfie braking system comprises a double disc unit at the front and a single at the rear, all hydraulically operated. The suspension is of the conventional telescopic fork and swinging arm variety but appears to have plenty of movement. Travel of 16cm is claimed for the front. The rear suspension has a two-stage damping force, which can be adjusted. Unlike the conventional single-unit handlebars, the CBX has unusual forged duralumin handlebars which are independently mounted. This permits the angle to be adjusted. The performance of the Honda giant is impressive. Not only can it exceed 200km/h with ease, but it can also cover a standing 400 m in 11.655. It can also reach 190km/h in 400 m from a standing start. Fuel consumption is quoted at 23km. lit, at 60km/h.