Twin shock-absorbers with adjustable preload 267-mm discs at either end took care of braking needs which meant that I could only use the revs for a few brief bursts. But that was enough to remind me how quick and how superbly versatile the RD was. Apart from daily commuting, my own RD introduced me to foreign touring, where the low-barred bike’s ability to cruise comfortably at an indicated 120 km/h ― its rider leaning comfortably on a tank-bag ― was very impressive. The large duel-seat was good for a pillion, too, although the two-stroke’s thirst meant the 16-litre fuel-tank emptied fast. The RD was happier still when being ridden hard on a racetrack. For my first season’s competition, I simply rode to the circuits, taped up the lights, swapped the licence-disc for racing numberplates, and lined up on the grid. I didn’t win any races against the tuned and generally faster opposition, but the RD was surprisingly competitive, never let me down, and survived all but one of several crashes to get me back home. Predictably, the RD400’s combination of performance and competitive price made it a big success. That continued for several years and through a handful of model updates. The RD400D of 977 had just cosmetic changes, notably a tail cowling, but the following year’s RD400E featured electronic ignition, revised porting, and new carbs and exhausts, boosting peak power to 44 hp. The chassis was also updated with thicker forks and folding, frame-mounted foot-rests. By this time emission legislation was getting ever tighter and Yamaha’s liquid-cooled RD350LC was under development for introduction in 1980. Before that came the 1979-model RD400F, featuring minor cosmetic updates over the C. It was as fast and fiery as ever ― a fine way to bring Yamaha’s magical line of air-cooled two-stroke twins to an end. For a revvy two-stroke, the RD was very well-behaved at low engine speeds, idling reliably, trickling through traffic happily, and pulling cleanly, if not particularly hard, from as low as 30 km/h in top gear. The rubber-mounted motor buzzed slightly at low revs, but that was never a problem, and the tingling almost disappeared once the speed increased and the engine came alive. “Its acceleration curve from 5,000 rpm is little short of frightening,” reported one contemporary tester and, although that seems ridiculous now, I could see why he was impressed. The Yamaha covered a standing quarter-mile in just over 14 seconds, more than half a second clear of its nearest 400-cc rival, and its top speed of 165 km/h was a match for any bike in the class. The combination of fierce acceleration and high-barred riding position could make the steering feel very light at times, but, in general, the RD’s handling was good. Sure, for track riding or even hard road use the Yam’s forks benefited from thicker oil and the standard rear shocks could usefully be replaced by an aftermarket pair from S&W or Marzocchi. But, at 165 kg with five litres of fuel, the RD was the lightest of the 400s and there were few 1970s bikes that could embarrass it in the bends. By modern standards, the Yamaha’s standard suspension felt a bit lacking in damping. The front brake had more lever travel and less power than I’d have liked, too, although the combination of single front and rear discs was highly rated at the time. I had no complaints about the nearly new pair of Avon Roadrunners on the Yamaha’s 18-inch wheels. Despite being quite narrow, the Avons gripped as well as I remember their predecessors doing all those years go. This bike’s engine was not fully run-in after a recent rebuild, 63 www.bikeindia.in July 2020 Bike India
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