Changes transform Honda’s CB750 sports roadster

Press, 29 July 1976, Page 10

Changes transform Honda’s CB750 sports roadster

It is seven years since the first Honda C 8750 roadsters rolled off the assembly lines in Japan, heralding the start of what has become known as the “superbike era.” But it is only relatively recently that major changes have taken place with the model. This year the classical shape of the original fourcylinder Honda, with its impressive array of exhaust pipes, has been replaced on the showroom floors in New Zealand with a vastly different machine incorporating many long overdue improvements — the C8750F. It is livelier, faster, quieter and handles better than the previous fourpipe model. With the new four-into-one exhaust system, the big Honda has increased ground clearance on the left, although it is possible to scrape the pipe on the right. This also markedly alters the appearance of the machine. And if you happen to fall over on the left some expensive bills can be avoided, even if that side of the bike now looks a little spartan. Although the changes that have been made are welcome the decision to produce an entirely new model must have taken considerable courage because the C 8750, as it was, was a very good seller indeed. It had required an almost legendary reputation for' reliability and sound workmanship. But the new machine is at least as good in this respect and considerably better in others. If anything, the touring stature has been enhanced. The front fork remains unaltered but the frame

has been completely redesigned and new rear suspension units with longer travel and better damping have been introduced. The fork trail has been increased by raking the steering head, giving the machine a much more secure feeling on tight bends. Internally, the four-cyl-inder, overhead camshaft, four-stroke engine is different from its predecessor. Oddly enough, it has returned to the original specification of the prototype 750 fours. The compression ratio has been increased slightly to 9.2 to 1 and a camshaft with a higher lift and greater duration is employed. The same power figures are quoted by Honda, although it can be safely assumed that the company

is taking a conservative view of this. The new engine appears to be very much livelier than the previous one without losing the wide spread of torque for which the Honda was so well known. It will pull away without snatch in top gear from 11 m.p.h. There are few other road machines capable of that. At the other end of the scale, it has a top speed in excess of 125 m.p.h. Acceleration is good, too. It takes 13.255ec to complete a standing quarter mile — a time recorded at the Motor Industry Research Association’s proving ground in England — and at the end of this distance is travelling at more than 100 m.p.h. However, these figures are slightly down on those obtained at the same

venue on a Honda C 8750 four in 1970. On that occasion, the test Honda flashed through the electronic beam at the end of its run in 12.6 sec and at 102 m.p.h. The 736 cu. cm engine, with its five main bearings, develops 67 b.h.p. at 8500 r.p.m. Its maximum torque of 44ft-lb is achieved at 1000 r.p.m. less. Gearing is lower overall by 8 per cent and the fourth and fifth ratios are now closer to third. In view of this, the acceleration figures are surprising. One can only assume that the machine originally tested was specially prepared for the occasion. Top gear flexibility is certainly much improved. The engine pulled very strongly from 4000 r.p.m. right through to the limit

at 9500 r.p.m. The delivery of power is beautifully smooth. Fuel consumption for normal use, remembering that this machine invited spirited riding, is abut 50 m.p.g. There is the usual hydraulic disc brake at the front, the Honda now has a similar unit at the rear. Both are UJin discs, hydraulically operated, and are both progress’ve and powerful. The brakmg distance from 30 m.p.h. is 27ft 6in. The fuel tank now holds four gallons and the filler cap is recessed under a lockabie flap. Lifting up the lockable seat reveals the battery and tray for the tools. At the rear is a small boot. The Honda is unusual in that it had dry sump lubrication.