Behind the Iron Curtain: 1958 Jawa 500 Overhead Cam Twin

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1958 Jawa 500 Overhead Cam Twin
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The single Jikov carburetor made tuning easy and helped give the Jawa good low-end pulling power.
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1958 Jawa 500 Overhead Cam Twin
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1958 Jawa 500 Overhead Cam Twin
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The Jawa 250 featured unit construction, an automatic clutch, a plunger rear suspension and a telescopic fork, making it one of the most technically advanced motorcycles of its day and earning it the nickname "Perak," or spring.
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The 500's ingenuity of design, quality of finish, and attention to detail was on par with BMW.
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The air filter for the single carb is integrated into the oil tank, a nice touch that helps give the Jawa an uncluttered look.
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Low and lean, the Jawa was among the best looking bikes of its day, a surprise given its proletarian origins.
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Low and lean, the Jawa was among the best looking bikes of its day, a surprise given its proletarian origins.
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Single overhead cam is driven by a shaft and bevel gears on the engine's right side.
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The overall feel is one of quality, reflecting a Jawa tradition that even their communist overlords couldn't suppress.

1958 Jawa 500 15/02
Claimed power: 28hp @ 5,500rpm (claimed)
Top speed: 91mph (claimed)
Engine: 488cc air-cooled OHC parallel twin, 65mm x 73.6mm bore and stroke, 7.0:1 compression ratio
Weight (dry): 370lb (168kg)
Fuel capacity/MPG: 4.2gal (16ltr)/45-55mpg (est.)

In 1960s Britain, motorcycles were still pretty much the number one commuter choice for Joe Public. And no, your average factory grunt wasn’t rolling to work on a Vincent or Velocette.

Even after the Honda Cub came on the scene, some of the most popular commuter bikes in England were small 2-strokes from Jawa and its sister company, CZ. A big part of their appeal was their low price: To garner “hard” currencies, the Soviet bloc flogged them off at budget prices. In 1965, London dealer Pride & Clarke advertised the twin-port Jawa 250cc Favorit for £120 ($335.50) including tax, while a 250cc BSA C15 cost almost £200 ($559)!

As working machines, most of these bikes were literally ridden hard and put away wet — if they were put away at all. Yet in spite of scant maintenance and chronic abuse, they just kept going. They were rugged and reliable, if also a little spartan, so it would come as a surprise to the average British biker to learn Jawa also built one of the most elegant, advanced and technically sophisticated motorcycles of the early post-World War II period. Yet the truth is, the 500cc Jawa overhead cam twin featured here was more in line with the company’s history of innovation and advanced engineering than their stodgy Soviet-era commuter machines.

The back story

Born in 1878, Frantisek Janecek worked for Czech armaments manufacturer Kolben until 1909, when he opened his own arms plant in Prague. With declining demand for weaponry in the 1920s following World War I, Janecek turned to making motorcycles powered by a 500cc 4-stroke single from German manufacturer Wanderer.

Although the new Jawa — a contraction of Janecek and Wanderer — sold well, Janecek saw the potential for smaller, simpler machines in the straitened economy of the 1930s. To this end, he hired British engineer George Patchett, who introduced him to the 175cc Villiers 2-stroke. Janecek designed a simple bolt-up, pressed-steel triangular frame with a rigid rear and pressed steel “girder” fork with friction damping. Though inexpensive (less than two-thirds the price of a typical 500cc machine), the Jawa 175 was durable, well-made and economical — perfect for the times. And like all pre-World War II Jawas, it was painted red!

Late in the 1930s, Jawa developed both side- and overhead-valve 350cc 4-stroke singles. But after Czechoslovakia’s annexation by Germany in 1938, the company was obliged to use its skilled workers and machine tools to make military equipment for the Third Reich. Frantisek Janecek died in 1941, leaving the business to his son Karel. However, work continued on the development of a 250cc 2-stroke single that was eventually launched in 1946, soon after hostilities ceased.

The Jawa 250 featured unit construction, an automatic clutch, a plunger rear suspension and a telescopic fork, making it one of the most technically advanced motorcycles of its day and earning it the nickname “Perak,” or spring. It won a gold medal at the Paris motorcycle show in 1948, and that year the factory built more than 17,000 of them. It was joined in 1948 by a larger 2-stroke 350cc twin-cylinder version in the same frame. This frame would go on to provide the basis for the 500cc overhead cam twin.

The OHC 500

In 1949, Jawa, which had been nationalized at the end of the war, was merged with former competitor Ceská Zbrojovka (CZ) and both companies came under communist control. Karel Janecek left the company — and the country.

It’s unclear why Jawa chose to build a luxury 500cc 4-stroke twin when they did. Perhaps it was a snub to the dour communist regime; a slight at the claimed technological superiority of their wartime occupiers, perhaps, or just to prove that in spite of their new mandate to build basic transportation for the proletariat they still could create superior designs.

Regardless, the first version of the Jawa 500 twin, model 15/00, arrived in 1952 featuring a unit-construction 488cc engine with dry-sump lubrication and an overhead camshaft driven by a shaft and skew gears. Valves were operated by rockers, and drive to the clutch and four-speed transmission was by chain.

The gearbox featured a semi-automatic shift mechanism: applying pressure to the shift lever disengaged the clutch, allowing the rider to shift gears without using the hand lever. This also meant the Jawa could be held at a stop in gear without using the clutch lever, simply by stepping on the shift lever instead. It’s essentially the system Triumph later introduced as the “Slickshift,” and Honda used on their Cub. Also innovative was the way the shifter and kickstart spindle were fixed concentrically — though it also meant the kickstart was on the “wrong” (left) side of the bike.

The drivetrain was dropped into essentially the 250/350 frame with the plunger rear end and telescopic fork. To accommodate the taller overhead cam engine, the frame was extended with a steel bar insert. Unfortunately, the extension was right where the centerstand attached, and the fragility of this arrangement was a concern to some owners.

However, the 500’s ingenuity of design, quality of finish, and attention to detail was almost breathtaking, and certainly on par with BMW. Examples include the air filter neatly encased in a cutout in the oil tank, the throttle cable running inside the handlebars, the elegant headlight nacelle (Triumph introduced theirs in 1949), the massive rear suspension plunger castings designed to prevent any “looseness” in the rear wheel, the inclusion of hydraulic dampers inside the plunger housings, and the discreet use of gold pinstriping.

An update to the 500, the model 15/01 arrived in 1954. The skew gear cam drive was dropped in favor of a more conventional bevel gear, and a dual seat replaced the cantilevered saddle of the /00. Claimed output was given as 26 horsepower. The same year, Jawa introduced two new 2-strokes, the 250cc model 353 and the 350cc model 354, both known as the “Kyvacka,” meaning swing, because of their swingarm rear suspension. However, the 500 continued with the old plunger frame.

The final version was announced for 1957, now with substantially larger full-width aluminum hubs containing 10-inch diameter drum brakes but still with the plunger frame. Output was now up to a claimed 28 horsepower, giving the model 15/02 a top speed of between 85-90mph. Unfortunately, a luxury touring motorcycle was not what the central planning committees of the Eastern Bloc wanted: Jawa had become a major supplier of motorcycles to the USSR, and concentrated production on the 350cc model 354, often sold with a sidecar. Production of the overhead cam 500 ceased in 1958.

Dale Baston’s Jawa 500

Jawa fan Dale Baston had been looking for an overhead cam 500 for 15 years before he finally found one in California. “When I was a kid in New Zealand, we had thousands of Jawa 2-strokes,” Dale remembers. “They were really popular. I knew nothing about the 500 because we never got any. Then I came across an article on one. I was a teenager, and I thought, ‘Wow, isn’t that something.’ And I always thought, it was in the back of my mind, that I wouldn’t mind getting one.”

However, finding one wasn’t easy, although the 1990 reunification of Germany helped. As far as Dale has been able to determine, the 500s were never exported to the West, so when the Wall came down, many East German imports appeared on the market for the first time. “They would only come up occasionally in Germany or the Czech Republic,” Dale says. “I think there’s only one, possibly two, in Britain.

“So then I got serious about it,” Dale says. “A friend of mine in Poland found one in the Czech Republic, and told the guy he wanted it. He said yes, but when he went to get it, the guy said, ‘sorry, I sold it to someone in Germany.’ And then the prices started to escalate.”

Dale saw a couple of sorry examples at a swap meet in the Czech Republic, but they were not much more than “bits and pieces.” It was on his return from that trip that he decided to try eBay, just on the off-chance, and found one in California. “I thought, well, they never show up on eBay,” Dale says. “I couldn’t believe my eyes.”

The 1958 model 15/02 on eBay had been restored in Germany some years before, but looked good in the pictures. Dale found he was bidding against an Australian who wanted to hear the engine run before committing. “I said I’ll take it without hearing it run,” Dale recalls, and he bought the Jawa. “I went down, picked it up and brought it back. It was virtually dead stock when I got it. And it had been nicely restored.”

However, there were some paperwork hassles. The 500 had never been registered in the U.S., so all Dale had was a German title. “It was registered in his wife’s [the former owner’s] name in Germany,” Dale says. “That was fine, but when I went to register it here (in Canada), they insisted on all the documentation being translated from German to English. So then I had to find an accredited translator.” It was a useful exercise, though, because the original log book contained valuable information on the 500 — it was more like an owners’ manual than a title.

On the road

The 500 required very little fettling before Dale was able to put it on the road. Something he did discover, though, was excessive lash in the bevel drive for the camshaft. It turned out the bushings were in spec, but the shaft itself was worn. “The bushings were absolutely spot on, they hadn’t worn a bit,” Dale says. “So I had the shaft hard chromed, reground it and put it back together.”

The previous owner had also removed the foot-clutch mechanism, which Dale replaced. “I put that back in just for the fun of it,” he says. “It works fine. You can sit at the lights in first gear with your foot on the gearshift lever and the clutch stays disengaged. They predated Triumph’s Slickshift by a number of years.”

And what about the weak centerstand. Has that been a problem? “It depends on how you treat it,” Dale says. “It works fine. You’re just aware of its weakness and allow for it.”

As for riding, Dale’s been pleased with the Jawa. “It’s very pleasant. It’s not a phenomenal performer, but for a 500 twin, it’s very smooth, very smooth indeed. It starts well, runs well and shifts nicely. In my opinion, it’s beautifully made. We tend to think that the Eastern Bloc turned out a bunch of rubbish.

“I like those massive drum brakes,” Dale says. “They’re not particularly fantastic but they sure look nice. I’ve seen some criticism of them in a couple of articles, but they work just fine. The suspension is reasonable, and the supports for the axle and the plungers are massive. They’ve got hydraulic shocks built in, so that’s quite a plus.

“And something that did quite surprise me,” Dale says. “It’s got magnesium crankcases! Why they would have gone to that expense and trouble I do not know. I was looking at it one day and I thought, they’re a different color. I didn’t think much about it. And then I read something about it in one of the magazines.

“It’s in outstanding shape and it is a very late one,” Dale says; he checked his bike’s serial number against those listed on the German-language owners’ forum. “Mine is later than any that are listed, so it’s got to be one of the last off. As far as I know, it’s the only series 02 bike in Canada.”

To my surprise, Dale offers to let me ride it around the block. The left side kickstarter takes some getting used to, but the other controls are easy to operate. The engine is almost free of vibration, and the assisted gearshift is light and positive. The steering feels neutral, and there’s no swaying or weaving like you experience on some plunger-suspension bikes. The brakes are adequate without being aggressive, and the overall feel is one of quality and sophistication, reflecting a Jawa tradition that even their communist overlords couldn’t suppress. MC

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