1966 Ducati Sebring

In 1958, Ducati was a producer of well-made and fast small single-cylinder motorcycles, mostly for the Italian market. Race fans knew Ducati from its wins in the lightweight GP racing classes, but the marque was not yet world famous. At that point, Joe Berliner approached the factory and pitched a deal.

Joe Berliner was the American importer for Zundapp and was looking to expand. Ducati liked the thought of the large American market and signed on. This was the start of a collaboration that lasted until the early 1980s. The Berliner Motor Corporation was good at marketing and quickly put a network of U.S. dealers together.

The first Ducatis imported to the U.S. were 175cc singles in touring (lower compression) and sport (higher compression) modes. The engine that powered these little critters was designed by legendary Ducati engineer Fabio Taglioni, and boasted a sophisticated design far in advance of similar-sized contemporaries built in other countries. The bevel drive single overhead cam engine ran a short stroke 8:1 compression ratio piston and provided power through a 4-speed transmission. The Marzocchi built suspension was excellent for its time, the frame was very stiff and the aluminum drum brakes actually stopped the bike. The styling was also advanced, with a “jelly bean” curved tank and an elegant color scheme.

A small motorcycle with beautiful styling and a penchant for roads in the hills was something new in America. “In the early Sixties, Ducatis simply amazed,” remembered Steve Anderson, writing in Cycle World. Period motorcycle magazines had to explain Ducatis to their readers. “These machines are sport motorcycles; they will appeal to the rider who is willing to forego some of the luxury features presently available, in order to get outstanding handling or performance or both,” stated Cycle in 1970.

Geoffrey Wood wrote a Ducati history article for Cycle World, which was published in the December 1966 edition. Claiming that Ducatis were the “most modern” of bikes then produced, the author pointed to the unit construction of the aluminum alloy engine, the excellent brakes in alloy drums, the overhead cam, and the Allen head bolts that attached the case covers. He waxed eloquent over the racing successes of the desmodromic valve racer — but skated over the fact that, in 1966, only purchasers of the production racers could get a Ducati with a Desmo head.

Desmodromic valves may have light springs, but the majority of the valve actuation is performed by short rocker arms that ride on extra camshafts. The extra complication and weight is made up for by the elimination of valve float. Motorcycles with desmo valves can rev high without concern. However, desmo valves are not only complicated, they are expensive to produce. As a result, up until 1968, the valves on the street bikes were actuated by antiquated hairpin springs.

Hairpin valve springs look like two side-by-side hair rollers. They roll tighter as the valve opens. They became popular in the 1930s due to the inadequacies of the alloys then available to make valve springs. Hairpins made out of vintage spring metal are more reliable than coil springs that are made out of the same stuff, due to different stress loads. As better valve spring metal became available, the disadvantages of hairpin springs (they are bulky and hard to enclose) became less tolerable. Another problem with hairpins was quality control issues. Scratches, even minute scratches, led to cracking and spring failure — which was the reason to install hairpin springs in the first place. The solution, polishing the springs, raised costs of manufacture.

From Diana to Sebring

With the 175 proven reliable, Taglioni cautiously increased engine size. In 1961, Ducati introduced the sporty Diana, and the next year, the lower compression Monza and a scrambler, all based on the same undersquare 250cc SOHC engine. The next step was to install a 5-speed transmission. However, that wasn’t enough for Berliner, conscious that the average American considered a 250cc roadgoing motorcycle to be teenage transportation. He pushed the Borgo Panigale factory to add some cubic centimeters to the little single.

Taglioni was not happy about the idea, but Berliner took way too much of the Bologna factory’s output to be ignored. He came up with the 76mm x 75mm (340.235cc) Sebring, which showed up in dealerships in 1965.

As a result of Taglioni’s concerns about overstressing the bottom end, the Sebring had a gentle camshaft, a restrictive carburetor, smallish valves, and a compression ratio of 8.5:1. Top speed was 78mph — slower than the 175 Sport, which, with a lightweight jockey and a level road, was good for just under 85mph. It was named for a Florida racetrack where a Ducati factor racer had won a race in the 350 class, even though the Sebring racer had nothing in common with the road bike except cubic capacity. Early roadgoing Sebrings had a tank and styling similar to the Monza, but less than a year later, the bike was restyled to look similar to the Diana, with a larger, angular tank. It handled beautifully, just like the other Ducati singles, but just wasn’t fast. Only 3,500 Sebrings were built through the three years of production.

In the meantime, Taglioni and crew were working on a stronger bottom end which could support more cubic capacity. The new version of the single cylinder machine, known as the “wide case” engine, debuted in 1968. About 200 Sebrings were built on this platform. Three years later, Ducati trotted out the V-twins that have been the emblem of the marque ever since. American Ducatisti flocked to the twins and, except for a few enthusiasts, lost interest in the singles. Many did not survive.

Little old bikes

Fast forward to 1982. Ducati was struggling through one of the down periods in its up and down history, and Ducatis, especially Ducati singles, could be bought for a song. Eric Mondale was then working at a Norton shop in St. Paul, Minnesota. It was late in the fall, and few customers were coming in the door. “There was no business at all after Sturgis.” In order to make a little money and stave off boredom, Eric bought a bunch of motorcycle parts and some used Safeway grocery carts. “Each one would fit an engine.” Unlike a lot of the other junkers Eric bought, this Sebring was more or less together. Eric built up the engine and reinstalled it. He also kept the bike, and when he eventually moved to the West Coast, he took this Sebring and another bike assembled out of the parts collection. At that point, Eric met Kim Williams, a master welder and European motorcycle enthusiast.

Kim Williams grew up on mini bikes. One of the landmark episodes of his childhood was the time he visited some relatives with his family. “They let me ride on a Honda with a CLUTCH!” He rode a 250cc Ducati Monza to high school, but eventually sold it in order to buy a bigger and faster bike. Kim grew up and became a journeyman welder, but he retained his love for small displacement motorcycles made in Italy.

Kim visited Eric one day and saw the Sebring. It wasn’t running at that point, and neither was the other bike that Mondale brought from Minnesota. The pair decided to restore the two bikes together and each keep one. The Sebring would be (visually) stock; and the other bike would be a special. They agreed that Eric would work on the engines and Kim would do the painting and assemble the cycle parts. At the time, Kim had a paint shop in his warehouse, which is where both bikes were painted.

Back in the day, the complaint most often heard about the Sebring was that it was slow. Taglioni’s concerns about the bottom end proved to be unfounded — the “narrow case” singles, including this Sebring, could take more lower end stress without problems. With the advantage of fifty years of hindsight, Eric decided the Sebring could go faster without a heavy infusion of cash. He installed a higher compression piston, polished the crankshaft and supported the lower end with roller bearings. Instead of the original 24mm Dell’Orto, the bike is carbureted by a 32mm Amal. Kim rewired the bike, changing the system from 6 to 12 volts in order to get bright lights and more choice in components and batteries. Rebuilding the shocks and replacing the sprocket and chain brought the handling back up to spec.

Installing hair pin springs requires a special tool. Since the Ducati factory version is no longer available, Kim made his own hairpin compressor (not hard for a master welder) and found it made the springs in his Ducati (relatively) easy to replace.

The bike back together, with the seat cover replaced by Mario’s in Alameda, California, the chrome work back from Meclec’s in Fresno, California, and a Dunstall muffler installed, it was time to go for a ride. Ducatis of this era have a strange looking side stand with an extra prong to make it easier to find the stand with a toe. Like many period Italian two-wheelers, the shifter is on the right, and both the brake and the kickstarter are on the left. Figuring out how to operate a left side kickstarter is a head-scratcher for many folks. However, you don’t have to be born in Padua or Napoli to figure out how to start this Ducati. The Sebring is very light (271.1 pounds) and has an easy to operate centerstand. Put the bike on the centerstand, fill the tank with premium gas, tickle the carburetor, and pull the compression release.

Now, kick two or three times without turning the key on — either astride the bike or standing to one side, your choice. Kim straddles the bike to kick. Using the kickstarter, push the piston two degrees past top dead center, turn the key on, then kick. “Sometimes it will start on the first kick, sometimes — it won’t.” However, the Sebring always eventually starts. Kim says it is very reliable.

The Sebring shifts one up, four down. All the work Eric put into the engine has really paid off in faster speed through all gears. “It pulls really well. I used to own a BSA Gold Star, and it pulls faster than the Gold Star,” Kim says. “Fifth gear is basically an overdrive. “It has no torque in fifth. Any grade, I shift back to fourth. It will thump along happily at 65mph. Nice gearing — you can stay in the powerband without any trouble. The brakes are amazingly good, especially the front brake. I have never had any issue with braking.”

Kim rides his Sebring around town and for short distances on a regular basis. He uses Lucas 20/50 oil, which is formulated for wet clutches. The bike does not have an oil filter and he changes oil every 2,000-2,500 miles. “Oil USED to be cheap!” Other than changing the oil, Kim doesn’t do much except lube the cables (Kim likes to lube cables on a regular basis) grease the chain, and check the tires. Every once in a while he will pull the spark plug out and check the color. He says the carburetor stays in tune and the points were set once and have not budged.

Despite the rarity of this 350, there are a surprising variety of parts for sale on eBay. Other parts are available on Ducati enthusiast sites, and, given the commonality of many Ducati singles parts, keeping this Italian single on the road has been problem-free.

“It’s a torquey little bike. It runs good in the hills, runs good on the freeway.” It is shod with Avon Roadrunners, which help with the good handling. Kim says the Sebring takes on really tight, twisty roads. “It’s light and easy to flick around.”

“I love this little bike. I sold my Monza to buy a 750 Norton Commando, and always regretted it. It’s nice to have this reminder of my youth — with a little more horsepower!” MC