Ducati GTL500 and First Pantah: Bike detectives

Date 19.1.2015

Presented by
  • Motorcycle Trader

blog-img

 

Ducati GTL500 and First Pantah 

If you want an ordinary bike, buy Japanese; if you want a sportsbike, buy Italian.” This lofty statement was made by Ducati’s general manager, Franco Zauibouri, in 1976.

Ducati was at the crossroads with three managers passing through a revolving door in as many years. It was selling less than 13,000 motorcycles a year. These were made up of around 5000 860 GT tourers, less than 1000 750/900cc SS sportsbikes and around 4000 of the underwhelming  GTL parallel twins, with the rest made up of the 125cc two-stroke enduro.

Ah, those parallel twins. Ducati management thought they would be a sales saviour, along the lines of Honda’s popular CB350-450 twins, but they put the company into an even bigger financial tank-slapper.

HEART OVER BRAINS

It would take three years to get back on track with an entirely new 500cc V-twin, designed by “Dr T”.

What is fascinating about this case is how the two stories overlap. While Ducati management was ploughing its efforts into a failure, its most trusted engineer was developing the engine that remains the basis of Ducati’s model range more than three decades later.

 The restored parallel twin featured here is from the first year of GTL production, 1975. Parked up beside a 98 per cent original 1980 SL from the first year of full-scale Pantah production, the pair bookend an amazing story.

 Australia has a huge link to these two models as we were a key Ducati market in the 1970s and ’80s. Italian motorcycle expert, Steve Craven (SCR Ducati in Morisset, NSW, ph: (02) 4973 4165), is a realist about the Ducati marque.

His famous quote is: “One of the most expensive things you will ever buy is a cheap Ducati”. So how did he get involved with the restoration of what’s considered the lemon of Ducati’s lineage?

  “I restore Italian bikes for a living, and usually only accept bikes that excite me,” he explains. “Like most Ducati owners, I was not that interested in the parallel twin range. Their reputation for unreliability and lack of V-twin character had kept us apart since the ’70s.”

REPUTATION ON THE LINE

His interest was sparked when a friend threw him the challenge of restoring this GTL in just five months to a standard that could survive 1700km on the recent Moto Giro in Qld.

No pressure then, especially considering it would be making its debut in front of those most severe of critics, fellow Ducati restorers and owners. This early first-series 500 GTL was fairly complete and original so did it really need a ground-up rebuild?

“Its Smiths speedo was showing almost 20,000km, or about the time most GTLs failed quite spectacularly,” Steve replies. “One of the main issues is the small steel plugs, pressed into the end of the cam, which have the nasty habit of coming loose and falling out at this mileage. This reduces oil pressure to zero with imaginable consequences.”

 The fix? Machine the rough casting inside the cam halves and fit an alloy plug with an O-ring to create an oil tight and permanent seal.

 What else is wrong with this design, which legendary Ducati designer Fabio Taglioni refused to be associated with, instead turning his attention to developing the much-loved Pantah range?

  Steve explains wearily: “Another unfortunate design ‘feature’ is the plain-bush main bearings, the shortcomings of which BSA had already proved with their A65 model in the 1960s. The camchain tensioner design (a chain-driven SOHC with valve springs was cheaper to produce than the bevel-desmo system) is not great either. I think you get the general idea.”

 So the GTL had a crank-up restoration, costing much more than the bike’s market value.

 “Several people in the know have said it is possibly the best GTL in the world, but I’m not sure if that is damning it with faint praise,” Steve says ironically. How did its public debut go?

“The resto was completed the day before we left for the Moto Giro, so I was only able to put about 17km on it,” says Steve.  “The usual jokes greeted our arrival, but all were impressed with the bike’s appearance. The first day of the ride the GTL started right up on the button with frost covering the bikes. It idled straight away and the Lafranconi exhausts give a quite un-Ducati-like sound.”

 The bike ran faultlessly during the five-day rally, only needing a rear chain adjustment.

 “Due to its newness we kept revs under 6000rpm, which still gave a top speed of 150km/h,” Steve says.  “Approached with low expectations, the bike didn’t disappoint. With good suspension and brakes it was easily a match for the fastest Giro bikes, usually 450cc Desmo Ducatis.”

 The factory claimed 35hp at 6500rpm and a dry weight of 170kg.

 Warren Lee, CEO of Ducati Australia, remembers the GTL well, as parent company Fraser Motorcycles had been a Ducati dealer since 1964 and Australia was now a major market for the factory.

“Sales got going for us when the Sport came along (in 1977) with its mini-Darmah styling,” he says. “The GTV did okay as well.”

By then a reluctant Dr T had been press-ganged into doing a desmo head conversion.

The model was soon to be eclipsed by the Pantah range but Frasers continued to sell the parallel twin, with the last batch of 76 produced for the Australian market in 1983.

Strange, because you’d think the Pantah would have set the local market on fire.

“We got at least a couple of the (163) pre-production Pantahs in 1979 and sold a reasonable number of the ice-blue SLs in 1980 but the 600SL did much better,” he says.

“I think it was probably the Aussie mentality of bigger is better. Don’t forget that the bevels were growing to 1000cc so the 600cc size seemed to make more sense for buyers.”

PANTAH PUNCH

Initially it may have been a sales slow-burner Down Under, but the Pantah range was a revelation to Ducati owners worldwide. Finally they had great performance coupled with reliability. A top speed nudging 200km/h, 180kg dry weight and 45hp at 9050rpm all added up to little hottie that punched well above its class.

Craven has this take on the Pantah experience: “When ridden in isolation, the 500SL is great fun, offering true 100mph-plus performance, great handling and that V-twin sound,” he says. “It only seems a little underwhelming when ridden alongside its larger brethren.”

He should know as he has the “full set” of Pantahs at his disposal, having restored the 650 and 750 F1 models, with a 600SL waiting its turn. The 500SL shown here is unrestored and its only non-original parts are the handgrips, bodywork screws and the tank protector.

 Australia has a huge link with this belt-drive L-twin, throughout its varying incarnations. Early racing success by engineers Bob Brown and Ian Gowanloch in the 1980s helped create a local legend. When its descendant, the 916 Superbike, came along, Troy Corser brought home an SBK world title. Troy Bayliss created another legend with his multiple wins in the category.

LAST WORDS

Let’s give the last word to the hardworking Steve: “It’s unfair to make a comparison between the Pantah and the GTL. One was an answer to a question no-one had asked, designed by bean counters who saw it as a mass-producible competitor to mainstream middleweights. Meanwhile, the Pantah was designed by Taglioni as a worthy successor to the mighty, but expensive to build and fragile, bevel-drive bikes.”

FAST FACTS ON DUCATI

1. Ignition points are one of the hardest parts to source for the parallel twin. Restorer Steve Craven fitted Sachs electronic ignition. “This is a great addition to almost any old Italian bike,” he says.

2. “I think one of the GTL’s best features is that it does not have any sporting pretentions, as most other Ducatis do, so this enables you to just enjoy the bike for what it is,” says   Craven.

3. Dr T. slaved day and night for years on his belt-drive version of the L-twin, with engines running on the dyno from 1977. Various engine configurations were tried, including experiments with a supercharged 350 in 1980.

4. Fraser Motorcycles Group is celebrating 50 years as a Ducati distributor. It is one of Ducati’s longest-serving distributors, having started in 1964. Since that time the factory has had seven different management teams.

CEO Warren Lee credits FMG’s success to constant visits to the factory and establishing a “model by month” production order.

“Since the 1960s we have travelled to Italy at least twice a year,” he says.  “We’re a key market for Ducati because of this communication and also giving the factory a month-by-month plan to get the models we want in the colours we want.”

Frasers has distributed Ducatis in New Zealand since 2001.

“We are looking at a 50 per cent increase in NZ sales this year,” Lee says.

“Combining Australasian orders means a buyer can go into a NZ dealership and get the model he wants quickly.”