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Yamaha RD 500LC Christian Sarron Replica

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Make Model

Yamaha RD 500LC Christian Sarron Replica

Year

1985

Engine

Two stroke, 50°-V4 cylinder, reed valve.

Capacity

499 cc / 30.3 cu-in
Bore x Stroke 56.4 x 50 mm
Cooling System Liquid cooled
Compression Ratio 6.6 :1

Induction

4x 26mm Mikuni carburetors
Ignition Digital CDI
Spark Plug NGK, BR9HS

Starting

Kick

Max Power

88 hp / 63.9 kW @ 9500 rpm

Max Torque

65.7 Nm / 48.4 lb-ft / @ 8500 rpm
Clutch Wet, multiple discs, cable operated

Transmission 

6 Speed 
Final Drive Chain
Gear Ratio

1st 2.250 2nd 1.685 3rd 1.363 4th 1.166 5th 1.043 6th 0.960

Frame Steel twin downtube

Front Suspension

37mm Air assisted telescopic forks, 4-way spring preload adjustable and anti-dive variable.
Front Wheel Travel 140 mm / 5.5 in

Rear Suspension

Monoshock, spring preload and rebound damping,
Rear Wheel Travel 120 mm / 4.7 in

Front Brakes

2x 267mm discs 2 piston calipers

Rear Brakes

Single 245mm disc  2 piston calliper

Front Tyre

120/80 V16 +

Rear Tyre

130/80 V18
Dimensions Length 2085 mm / 82.1 in
Width    705 mm / 27.7 in
Height 1145 mm / 45.0 in
Wheelbase 1375 mm / 54.1 in
Seat Height 780 mm / 30.7 in

Dry Weight

180 kg / 437.8 lbs
Wet Weight 198.6 kg / 436.5 lbs

Fuel Capacity

22 Litres / 5.8 gal

Consumption Average

27.5 mpg

Standing ¼ Mile  

11.7 sec / 117.7 mph

Top Speed

148 mph / 238 km/h

 

Few superbikes have been as eagerly anticipated as the RD500LC. In 1983 the long-standing success of Yamaha's middleweight two-stroke twins, combined with the factory's success in 500cc grand prix racing, made a 500cc four-cylinder race replica seem the logical next step. Such was the demand that some magazines went as far as publishing spoof road •tests of a machine that did not exist.

 

When Yamaha finally put the real thing into production in the following year, few who rode one were disappointed. The RD500LC looked superb, with a racy full fairing in red and white colours similar to those of the factory OW76 that Eddie Lawson was riding to victory in that season's world championship. Like Lawson's racer, the 500LC was powered by a liquid-cooled V4 two-stroke engine. The roadster produced 90bhp. weighed an equally impressive 392lb (178kg) dry, and screamed to almost 14()mph (225km/h).

 

Two-stroke heritage

Rather than being developed directly from the racebike engine, the LC's 499cc, 50-degree V4 powcrplant was essentially two RD250LC units with bottom ends geared together, and with a gear-driven balancer shaft to reduce vibration. Induction system, engine porting and exhaust design were very different to the OW76 racer's, but bore and stroke dimensions of 56.4 x 50mm were almost identical, and the roadster also shared features including exhaust power valves.

Apart from the addition of lights and other roadgoing necessities, the main chassis difference between roadster and racer was that the RD50()LC's frame was made from square-section steel tubing instead of aluminium. This was still one dramatically purposeful streetbike though, with high quality chassis parts including anti-dive equipped telescopic forks, plus a single rear shock unit positioned horizontally beneath the engine.

 

The Yamaha's look and specification were mouth-watering, and its performance lived up to expectation. In typical two-stroke fashion the V4 felt flat at low revs, then came into its power band at 6000rpm with a crackle of its exhausts and a blast of acceleration that sent the lightweight machine shooting forward at breathtaking rate. That meant that in top gear it came alive only at about 100 mph (161km/h). Fortunately. Yamaha had supplied a good pair of mirrors.

 

 

Even more importantly, the 500LCS handling was a match for its motor. As well as light and quick steering, aided by its 16-inch front wheel, it was stable in slower bends and high-speed curves alike. Sometimes the front end got slightly twitchy when the bike hit a bump under acceleration. But that was no real problem, and the Yamaha's powerful triple-disc brake system was among the best in motorcycling.

 

Yamaha had succeeded in creating a bike that felt like a racer on the road, and the RD500LC proved its ability on the track with victory, against many big four-strokes, in Australia's prestigious Castrol Six-Hour production race. In the showrooms it was less successful, despite all the pre-launch hysteria. Drawbacks included poor fuel consumption, vibration, mediocre finish and a high price. Perhaps the real problem was that the RD500LC was just a little too much like a real racebike for its own good.

 

Source of review: Fast Bikes by Roland Brown