Yamaha RD500LC
 | |
| Manufacturer | Yamaha |
|---|---|
| Also called |
RZ500 RZV500R |
| Production | 1984 - 1986 |
| Class | Sports |
| Engine | 499 cc liquid-cooled V4 two stroke |
| Power | 64.2 kW (88 PS) @ 9,500 rpm |
| Torque | 65.4 N·m @ 8,500 rpm |
| Transmission | 6 speed |
| Weight |
205 kg (452 lb) (dry) |
| Related | Yamaha RD350LC (YPVS) |
The Yamaha RD500LC is a high-performance, two-stroke sports motorcycle, also known as the RZ500 in Canada and Australia. A lightened but detuned version known as the RZV500R was developed for the Japanese home market. Strict United States Environmental Protection Agency regulations meant that the RZ500 was not available for sale in that country. Produced for a short period between 1984 and 1986 it has become a sought after collector's machine.[1]
Development
With the success in the early 1980s of Kenny Roberts and the Yamaha YZR500 in Grand Prix motorcycle racing Yamaha realised that a road going replica of their 500 cc racing machine would sell well. Using the similar technology of the smaller RD series of two-stroke motorcycles the RD500LC was launched in 1984.
Design
Engine
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The RD500LC uses a 50-degree, twin-crankshaft V4 engine layout. Linked Yamaha YPVS exhaust power valves are controlled by a single electronic unit and servo motor and are designed to give a broader power band. The engine also features intake reed valves unlike the YZR500 racer which used rotary disc valve induction. The reed valves use two different intake arrangements, the lower cylinders are fed through crankcase mounted reeds; the upper pair use cylinder barrel mounted reeds. The four Mikuni carburettors are side mounted in pairs and feed each cylinder through 90 degree intake manifold. The lower expansion chambers exit normally but the upper pipes cross over each other just behind the exhaust ports to maintain the correct tuned length.
The dual crankshafts are geared directly to the clutch, while the front crankshaft also drives a counter balancer shaft mounted between the two crankshafts. The counterbalance shaft, unusual on a two-stroke, assists with dampening engine vibrations. The engine is cooled by thermostatically controlled liquid cooling, an auxiliary electric fan mounted behind the radiator cuts in at high temperatures (e.g. when stationary in traffic). Lubrication is by direct injection in to the inlet manifolds using Yamaha's 'Autolube' pump system. Normally controlled in other two-stroke engines by throttle position, the engine oil pump is controlled by the YPVS servo motor ensuring that the oil supply is not shut off at high engine revolutions.[1][2]
Transmission
The RD500LC uses a six-speed sequential close ratio gearbox, the gear shafts are removable from the right side of the engine without the need to split the crankcases. The clutch is of the wet, multiple-disc coil spring type and is cable operated. Unusually for a two-stroke engine the gears and outer crankshaft bearings are lubricated by a separate crankshaft driven troichoid oil pump. Final drive is by O-ring chain and sprockets.
Chassis
The frame of the RD500LC is manufactured from mild steel box-section and uses a perimeter layout. The rear shock absorber is unusually placed horizontally under the engine and uses the lower crankcase as a mounting point. The under-seat area is occupied by the upper cylinder exhaust chambers, the battery and the YPVS servo motor. The rear of the shock absorber connects to an extruded aluminium alloy swinging arm via several forged aluminium rocker arms. An unusually small diameter 16-inch wheel is held between 37 mm (1.5 in) spring and oil damped forks which featured adjustable anti-dive units.
The RD500LC uses twin ventilated disc brakes for the front wheel with a single ventilated disc at the rear. A solo seat cowl was originally provided to cover the pillion seat when not in use.[1]
Electrical system
The RD500LC features a standard 12 volt electrical system. Yamaha's self-cancelling indicator unit is used and a variable resistance gauging system is used to monitor two-stroke oil tank contents with associated warning lights. Nippondenso capacitor discharge ignition (CDI) is used in conjunction with two coils.[3]
RZV500R
The RZV500R was designed exclusively for the Japanese home market although many have been exported privately. The RZV500R features upgraded parts not found on the standard RD500LC and RZ500 . A major difference is the hand-welded aluminium frame, which is significantly lighter than the steel version used on standard models.
The front forks are air assisted with rebound damping adjustment. The rear brake and gear levers are cast from aluminium, as are the clip-on type handle bars. These chassis modifications added up to a weight saving of 20 lb (9.1 kg). The engine was detuned to 64 hp (48 kW) to comply with Japanese legislation, this was achieved by restricting the internal diameter of the exhaust pipes and changes to the carburettor jetting .[1]
Models by country
Differences mentioned are comparisons to the UK specification RD500LC, Yamaha model numbers are in brackets where known.
- Australia
- RZ500N (53G)
- Austria
- Front and rear yellow side reflectors
- Canada
- RZ500S (1VW)
- Denmark
- Self retracting sidestand, right dip headlight
- Finland
- Self retracting side stand, extended rear mudguard, right dip headlight
- Germany
- Reduced load capacity (205kg instead of 211kg), self cancelling indicators deleted, right dip headlight
- Japan
- RZV500R (51X)
- Norway
- Self retracting sidestand, suppressor spark plug caps, right dip headlight
- Sweden
- Modified exhaust pipes, self retracting sidestand, right dip headlight
- United Kingdom
- RD500LC (47X early models - 1GE late models)
Specifications (RD500LC/RZV500R)
| RD500LC[1][3] | RZV500R[1][3] | |
|---|---|---|
| Engine | 499 cc (30 cu in), 2-stroke, four-cylinder, liquid-cooled, reed valve induction with YPVS | |
| Bore Stroke | 56.4 mm × 50.0 mm (2.22 in × 1.97 in) | |
| Compression Ratio | 6.6:1 | |
| Fuel System | Mikuni VM26SS 26 mm (1.0 in) carburettor x 4 | |
| Lubrication | Yamaha Autolube two stroke injection, transmission gear pump. | |
| Ignition | Capacitor Discharge Ignition (CDI) | |
| Transmission | 6-speed, constant mesh | |
| Final Drive | 530 chain, 102 links | |
| Overall Length | 2,085 mm (82.1 in) | |
| Overall Width | 705 mm (27.8 in) | |
| Overall Height | 1,145 mm (45.1 in) | |
| Seat Height | 780 mm (30.7 in) | |
| Ground Clearance | 145 mm (5.7 in) | |
| Wheelbase | 1,375 mm (54.1 in) | |
| Dry Weight | 205 kg (452 lb) | 196 kg (432 lb) |
| Suspension Front | Telescopic, coil spring, non adjustable spring preload, brake linked anti-dive system | Telescopic, air assisted coil spring, adjustable spring preload, adjustable rebound damping with brake linked anti-dive system |
| Suspension Rear | Link-type, gas/oil damped, 5-way adjustable spring preload, 4-way adjustable rebound damping | |
| Brakes Front | Dual hydraulic disc | |
| Brakes Rear | Single hydraulic disc | |
| Tires Front | 120/80-VR16 | |
| Tires Rear | 130/80-VR18 | |
| Fuel Tank Capacity | 22 L (6 US gal; 5 imp gal) | |
See also
References
- Notes
- References
- Yamaha RD500LC (47X) service manual, Yamaha Motor Co. Ltd 1st edition, June 1984
- Yamaha RD500LC (1GE-Europe) parts manual, Yamaha Motor Co.Ltd, 1985
- Motorcycle.com The Grand Prix fantasy
External links
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Wikimedia Commons has media related to Yamaha RD500LC. |
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