Midsize Marvel

Ducati 500 SL Pantah

Of the European makers Ducati is among the youngest, due to its post WWII startup. That might explain the company’s knack for producing the forward thinking technology Ducati Ing. Fabio Taglioni is remembered for. Living in an age when phrases like ‘iconic’ and ‘legendary’ are easily tossed, the praise directed at Taglioni is justified. Not all of the mechanical platitudes reached by Ducati were from Dr. T, but he made most of them possible.

Being a fan of the angular style popularized by rival De Tomaso, I’ve long been drawn to the 500 SL and the Pantah models that followed. However, there remains some confusion regarding Taglioni’s motivation in designing it. Some believe Ducati wanted a mid-size sprinter more appealing than the 70s parallel twin previously rolled out by the factory, while others believe Taglioni saw the Pantah as Ducati’s future. It’s possible both theories are fact, for soon after Cagiva’s 1985 buyout the bevel was phased out for belt drive twin, including a larger version with liquid-cooling and 4v heads for the 851 Superbike. As displayed here, the original 500 SL offered increased simplicity which translates into lower production costs. Ultimately, performance was increased due to lighter weight and a more compact construction.

Measuring two-inches shorter between the axles than a contemporary Desmo 900, Taglioni’s work to downsize the Pantah began with its trellis frame. Viewed from the side, sections of straight tube angle to form a simple ladder; two horizontal bars from steering stem to sub frame and three vertical, the rear most looping under to attach a mainstand. From this, the engine connects up inside with two tabs between the cylinder splay and four more tabs (two per side) behind the gearbox. Keeping the wheelbase short, a tunnel cast into the rear most crankcase holds the swingarm pivot and strengthens the assembly, which is made simpler with a conventional two-shock suspension. Both the fork and shocks are Marzocchi, the front with 35mm tubes. Uniform 260mm discs are fit and pinched by small 1p calipers, all from Brembo. My research shows OSCAM wheels were fit to early versions, then split-spoke FPS hoops. Fully gassed, the 500 SL weighs in at a feathery 430-lb. Viewed at different angles, there a hit of the 91-on 900 Super Sport in the fairing’s nose. Basic and now durable, the 500SL successfully reshaped Ducati production.   

Looking familiar in the traditional L-twin layout with the front cylinder canted forward, the engine was all new. Technically, it’s a 90-degree, SOHC twin with two-valves per cylinder measuring 499cc from an over-square 74 x 58mm bore and stroke. New cast aluminum crankcases did away with the kick start mechanism and featured high pressure oiling for the forged, plain bearing crankshaft; both departures from previous Ducati practice. The engine’s spin-on oil filter was new but the cylinders retained Ducati’s trademark vertical/horizontal finning. Becoming more popular during this era and only used on upscale models the Pantah’s bores used hard Nikasil coating securing domed 9.1 pistons. Formerly driven with elaborate rows of gears and shafts that Desmodromic magic was now generated via a toothed belt. Hidden under alloy covers the bottom pulley is driven via a jackshaft from the crank and connects belts running through a series of idlers and around each camshaft pulley. This new system not only worked, but remained reliable; good for 12K before needing replacement. Huge for a 500cc engine, the SL fits twin 36mm Dell’Orto PHFs that worked with a new digitized ignition. A wet, multi-plate clutch drives a five speed gearbox. With a factory rating of 50 HP @ 8500 rpm, the Pantah powers through its tall gearing to generate an honest 120-mph.

In a test published in May of 1981, Cycle’s editors coaxed a best ¼-mile time of 13.66 seconds –  shifting the engine some 1800-rpm past its 8000-rpm redline. The test noted even quicker figures were earned by European editors who spun the engine into five-digit territory. Unreal! “The Pantah’s dragstrip time surprised us…it felt slow on the road,” wrote Phil Schilling, himself an esteemed chapter in Ducati lore. “The engine’s smoothness, flat torque and the fairing’s still-air pocket send a false ‘seat of the pants’ sensation.” Ground clearance and handling also received praise, the latter benefiting from perfectly spaced transmission ratios and zero driveline lash. “The Pantah’s suspension lacks the adjustability of top Japanese models but this is forgivable. As a one-dimensional sportsbike, the 500SL remains calm over normally troublesome cracks, bumps and dips…unruffled and unaffected at speed.”

This somewhat original, low mile example sold in Vegas January 2018 for just under $9000, making the 500cc twin a somewhat affordable entry into the inner circle. No machine (to my knowledge) is gaining value more quickly than Ducati’s early bevel and Desmo Super Sport models, and the 500SL claims the very same engineering heritage. If other models from this era are any indication, the current low buy-in  may not be the case for long, especially considering the historical importance of the 500SL as a breakthrough machine. I’m taken with the 500’s light weight, subtle yet tasteful graphics, angular lines and logic as a backroad performer. Truly a stable, forgiving sports machine one can ride without fear of financial reprisal. Later 600 and 650 versions offered improved reliability (improved gearbox, starter) and a hydraulic clutch system. Buy to ride or sell for profit, the Pantah 500SL is a win-win. Nolan Woodbury

Ducati Pantah 500SL

Engine: Air-cooled, 499cc 2v 90° v-twin
Desmodromic/S.O.H.C. belt
Intake: 2- Dell’Orto PHF 36mm
Transmission: Five-speed
Clutch: Oil-bath multidisc

Chassis: Tube steel trestle frame
Front suspension: 35mm Marzocchi teles
Rear suspension: Marzocchi
Front brake: 2-Brembo 260mm
Rear brake: 1-260 mm
Weight (dry): 403-lb

Top speed: 120-mph

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