YAMAHA R6 TECH
For its entry into the hotly-contested 600 Supersport showroom stakes in 1999,Yamaha designers used the same family values as the mould-breaking R1 hypersports launched one year earlier.the result was a bike that similarly moved the technical goalposts in its field.
Head of the R&D team charged with creating the R6 was the man also responsible for developing the R1, as well as the new R7 with whichyamaha were also aiming for World Superbike supremacy in 1999: the father of the ‘R-concept’ bike family, Kunihiko Miwa. Nicknamed ‘Mr No-compromise’ inside Yamaha because of his focused intent to build the ultimate sports bikes in each capacity class, Miwa not only didn’t believe in cutting any corners in pursuit of that ideal, he also extended the same original technical thought inherent in the R-family design concept to the way in which such bikes are ridden.
“The R1 is like a bull – it has brutal performance which is difficult to exploit to the maximum, and takes a lot of experience to control,” Miwa-san told me. “But the R6 is like a horse – it’s easier to take to its limits, and to exploit the full potential of its design. In that sense, it’s like a four-stroke version of a 250cc GP two-stroke, whereas the R1 is more like a 500, where you brake late, square off the corner, turn sharply, then pull the bike upright and accelerate. With the R6 or 250, you brake early, and corner in a wide, sweeping arc to keep up corner speed, using high rpm acceleration and balanced handling.
“This determined the way we designed the new bike, integrating the rider with the machine to deliver easy-to-control cornering with extreme bank angles – the R6 can be leant over as much as 56 degrees from vertical without touching the ground. And to deliver 250Gp-type performance, we set ourselves the target to produce the bike which is the lightest, fastest and most powerful in its class, using technology found on the R1.”
That meant starting back in 1995 with the same overall design concept but a clean sheet of paper, for unlike some 600s like, say, the Suzuki GSX-R600 which were scaled-down versions of bigger bikes, the R6 shared no major parts with either the R1 or R7. However, like the R1, it usedyamaha’s revolutionary triple-axis engine format, whereby the gearbox shafts are stacked one above the other to deliver an extremely short and compact engine design that helped the unclothed 1999 R6 look more like a 400cc bike that a 600 – it was tiny.
The engine again followed R1 practice in forming a fully-stressed part of the all-new aluminium chassis design termed Deltabox II, which though claimed to be 20% more rigid than the oldyzf600thundercat frame at the headstock, was also 40% lighter, with thicker engine mounts but holes cut in its spars to improve the stiffness-to-weight ratio.
The rear sub-frame was detachable, for ease of replacement or repair in racing use.to help give maximum stiffness to the frame, a one-piece engine crankcase was used which, combined with the shortened three-axis format, resulted in the same long swingarm as on the R1, to improve traction and grip. But unlike on other Supersports, the R6 aluminium swingarm was heavily braced to avoid distortion under severe side loads from race tyres which are approved original equipment for the bike.
The conventional fully adjustable 43mm fork was chosen by Miwa for its reduced unsprung weight compared to an upsidedown type, set at a rake of 24-degrees but with just 81mm of trail and a 1380mm wheelbase – geometry worthy of the 250cc GP bike Miwa and Co had targeted as their design brief. And with a claimed dry weight of just 169kg, the R6 had to be ballasted to meet the 168kg four-cylinder minimum weight limit for World Supersport competition, once street equipment has been removed for race use!
At 65.5 x 44.5 mm, the 599cc R6 engine has a much longer stroke than the oldyzf600 motor (62 x 49.6mm) also used in the Bimota YB9, but the same dimensions as the Suzuki GSX-R600 – yet not such an ultra-short-stroke format as the existing ZX-6R Kawasaki (66 x 43.8mm) or the new CBR600 Honda (67 x 42.5mm).yet despite that, though, the R6 substantially out-revved any of its rivals, with a 15,500rpm redline and extra top-end power available via the ram-air system, as more cold air was shoved into the air-box via the pressurised ducting.
1999 BELGARDA YAMAHA YZF-R6
Liquid-cooled DOHC 16-valve transverse in-line four-cylinder four-stroke with offset chain camshaft drive 65.5 x 44.5 mm 599cc 123bhp at 14,500rpm (at gearbox) 13.5:1 4 x 37mm Keihin CVRD with TPS throttle position sensor Belgarda Yamaha CDI + 12v battery 6-speed Belgarda Yamaha close-ratio gearbox with electric start Multiplate oil-bath Cast aluminium Deltabox II twin-spar frame Front: 43mm Yamaha telescopic forks with Belgarda Yamaha internals. Rear: Cast aluminium swingarm with Öhlins shock and rising rate linkage 24 degrees 1380mm 81mm 167kg with oil/water, no fuel 52/48% static Front: 2 x 300mm Carbon Lorraine steel discs with four-piston Sumitomo calipers Rear: 1 x 220mm Belgarda Yamaha steel disc with two-piston Sumitomo caliper Front: 120/70-17 Michelin Pilot on 3.50 in. diecast Yamaha wheel Rear: 180/55-17 Michelin Pilot on 5.50in diecast Yamaha wheel 274kph (Monza 2004) 1999 Belgarda Yamaha Racing Team, Lesmo, Italy tyres, which only started to become a little unstable under power right at the end of my stint on the Bontempi bike, when they started to chatter a little, too, when running over any bumps in a turn. Still controllable, though.
The Yamaha’s trademark architecture, with its triple-stack gearbox layout, short engine with slanted cylinder block and long swingarm, gave excellent traction as well as lots of weight on the front wheel (52/48%), for extra grip in turns – again helping maintain corner speed safely. But it wasn’t as unstable under heavy braking as its R7 Superbike sister had been when I’d ridden it at the start of that year – and the 300mm Carbon Lorraine discs fitted to the Belgarda Yamaha, matched to the stock one-piece Sumitomo calipers which were by then the benchmark stoppers in the Supersport class, gave outstanding braking. They were sensitive without being snatchy, with lots of bite yet controllable modulation: definitely one of the strong points of an already impressive bike.
We knew when Yamaha unveiled the R6 at the end of 1998 that this had all the makings of one of the great bikes of our time in any class – on road, as well as track. Its performance in its debut World Supersport season cemented that impression: the Belgarda Yamaha was a taut, responsive, powerful and goodsteering motorcycle refined from an already outstanding streetbike, and was now surely ready to win a World title – as Jörg Teuchert obliged by doing in 2000, 20 years ago this year. For 1999 was only ‘Year One’ in the Yamaha Supersport game plan – and the Belgarda team had at that stage only scratched the surface of a bike brimming with potential.
"We’re gonna have to start working on it seriously now," joked Giulio Bardi after my ride. "But, seriously, this is a bike that was born well – as good for privateers as for privileged teams like ours, because it has a powerful yet reliable motor, and a good-handling chassis that’s responsive to set-up. But we’re still only climbing the R6 learning curve – it’s a good bike already, but next season onwards, it has the potential to be even better."
Prophetic words, indeed – borne out by those eight World titles.