1978 Ducati 500 GTL for Sale

1978 Ducati 500 GTL Red L Front

If you’re a motorcycle fan, you’re probably familiar with Ducati’s iconic v-twin [or “L-twin”] engine.  And if you’re a vintage bike fan, you probably know all about their tower-shafts and bevel-drive cams and the famous desmodromic valvetrain.  You might even know about their line of single-cylinder sport and offroad machines.  But most people, even Ducati fans, don’t know about their abortive attempt at a line of parallel twin motorcycles that was intended to replace or at the very least supplement the expensive and hard-to-package vee engines.

That might be because Ducati themselves don’t exactly celebrate this particular bit of history…

Vee engines are generally very narrow, but they can be problematic packaging front-to-back.  Go with a narrow angle, like the 45° Harley-Davidson, and you end up with a compact design [unless you also saddle them with a heavy, archaic, pre-unit gearbox and primary belt drive…], but one that tries to vibrate your eyeballs out of your skull and doesn’t want to rev very high.

Go with a wider angle for perfect primary balance, like Ducati’s 90° twin, and you end up with something very smooth and revvy, but pretty hard to fit into a short-wheelbase, quick-turning machine.

1978 Ducati 500 GTL Red Dash

So when the time came to develop a new, middleweight sporting machine, Ducati went back to the drawing board and came up with…  A parallel twin.  Hey, it worked for the British, right?  Predictably, Ducati engine guru Fabio Taglioni was appalled and insulted by the new direction and washed his hands of the whole thing.

The 500cc parallel twin engine had its valves actuated by springs instead of Ducati’s famous Desmodromic valvetrain and a single overhead camshaft.  It made about 35hp, perfectly acceptable for a machine of that displacement.  Unfortunately, Ducati folks can be a particular bunch, and the styling of the bike was not well received.  Even Taglioni’s eventual Desmo head couldn’t spark much interest, although it probably didn’t help that the bikes had a pretty high incidence of catastrophic engine failure…

1978 Ducati 500 GTL Red Engine

Fortunately, Mr Taglioni had a redesigned vee engine waiting in the wings that replaced the expensive to build tower shafts with simple rubber belts.  Derivatives of this engine can still be found in brand new Monsters at your local [ha!] Ducati dealer.

This particular 500 is very unusual in that it has been customized with a classic cafe style: 1978 Ducati 500 GTL for Sale

From the original listing:

1978 Ducati 500GTL (VIN- 503184, completely restored and upgraded as a “Hooligan bike” / café racer, powder coated frame and other parts, K and N filters, period correct Tommaselli alloy clip-on handlebars and throttle, John Bull rear sets, 900ss style oversized Dellortto carbs, stainless fasteners, Bub Conti mufflers, period correct racing rear air shocks, Borrani alloy rims with stainless spokes, lots of other upgrades to electric, etc., extensive spares! Sold with Bill of Sale). 
Not much information in the ad, but the photos speak volumes.

I happen to like this bike, although parts availability might be a very real problem, considering how rare it is.  It’s a handsome machine, and looks to be in very good condition.  If you’re a handy mechanic or love to scour the internet for parts in your spare time, this could be a very cool choice for a classic ride.

-tad

1978 Ducati 500 GTL Red Rear Wheel

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2 Responses

  1. Eric says:

    I had one of those and had the catastrophic engine failure (crank bearing).
    Nobody mentioned that the pistons are not configured like a typical parallel twin. The pistons are 90 degrees apart on the crank to make it sorta, kinda a V-twin. It had a funny sound to it.
    I had a friend with a 450 Suzuki at the time. It was more reliable and got better gas mileage.

  2. David says:

    It’s a well known fact that Ducati importers/dealers did not put enough oil in these engines when they came to the states, it was suggested that the cranks were made wrong, and in fact Ducati did revise engine cranks shafts at one point, chances are they may of had a bad run of cranks, but the rest of the package did not weather well, the ignition system is something even your best mechanics with have difficulty setting up, perhaps this also a reason for broken cranks. The first thing that comes to mind on these bikes is that they have no balance shaft to dampen vibration. Chances are if you have one, and it runs fine you got a good one.

    For starters I would shit can the points ignition as it’s way to much work for a average biker, install a pointless ignition system(points are no longer available NOS) though you can use a later 500 GTV breaker plate assembly that uses standard L twin points or Vespa style points then add some hotter ignition coils, by-pass all connections under the gas tank that are related to the ignition system with a heavy duty connector, the little 2mm harness pins just can’t carry that much amperage especially if they are dirty or corroded from sitting for 35+ years, the same goes for the ignition switch a good cleaning is in order…