Photo Feature
Race-Ready RD500LC

Owner: Giuseppe Natalini, Rome, Italy

I started to update my '85 RD500 many years ago, and at the time I didn't have an end target in mind. The sportbikes available in the market at that time were big, heavy, ugly and "four-stroke." I was looking for something "special," a 500GP replica two-stroke!

After tons of early modifications, two years ago I finally understood (better late than never) the best way to build up my RD500 was to have a clear target in mind. And that target was: just enough engine power to not compromise reliability but still have plenty of bottom and middle rpm thrust. Ultimate handling, and lightness as much as possible, too.

I use my RD on racetracks only. Everyone who has tried their street motorcycle on a racetrack knows that's a hard test for a bike. Everything must work at 100% - engine, carburetion, gears and suspension. Well, after finishing my project, I can say only one thing about my bike - this machine is absolutely wonderful!

Note: All photos are links to a larger image


  • 500cc, V-4, 2-stroke
  • Pistons are shorter than standard, and reshaped to have the same weight on each cylinder. Using TZR125 pistons
  • Exhaust ports measure 37mm in diameter, worked at the limit of the YPVS valve, instead of std 32mm
  • Reed valves reshaped and measure 37 x 37mm, worked inside for 16+3 mm, instead of std 30 x 37.5 mm. Fiberglass reeds are by Aktive
  • Removed friction gears from both sides of crank, and removed autolube pump
  • Std 26mm Mikuni carbs, now with adjustable main air jet
  • Using standard air box with modifications inside and UNI filter
  • Special Jolly Moto pipes, carbon fiber silencers

  • USD Kayaba forks with internal damping modifications and Ohlins springs. Ohlins rear shock
  • Marchesini magnesium 3.50 x 17 front with 110/70 x 17 race compound PIRELLI SUPERCORSA SC1 tire. Marchesini 5.50 x 17 rear with 180/55 x 17 race compound PIRELLI SUPERCORSA SC2 tire
  • Brembo gold series 320mm discs with double piston calipers, and Nissin pump. Rear brake Brembo gold series 220mm
  • 38/15 final drive gearing. DID 520 Pro Lightweight O-Ring chain with Ergal rear sprocket
  • Fiberglass fairing and rear section by ROC-YAMAHA '92
  • 155 kg (341 lbs) dry weight

Have any questions on the production of this bike?
E-mail Giuseppe here.

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