The Mysterious AJS 10R: A Motorcycle Detective Story
"British motorcyclists knew that the AJSs and Matchlesses in dealers’ shops in the 1950s and 1960s were one and the same, differing only in badges, transfers, and the shape of their silencers. In the 1930s, the parent company, Associated Motor Cycles, had made the marketing decision to continue producing the two marques, as each had its loyal following. At the height of its prosperity in the late 1950s, AMC offered a full range of single and twin cylinder-powered machines under both logos. This practice gave rise to the term badge-engineering, and while AMC was hardly the sole perpetrator, the London factory carried it to considerable extremes.In the 1960s, buyers looking for a 750cc heavyweight twin could choose an AJS, a Matchless, or a Norton, all assembled from the same parts bins.
When AMC collapsed in 1966, only Norton survived, living on in various government-subsidized amalgamations before finally expiring more than a decade later.
On the racing side of the ledger, AMC followed a different strategy. After the takeover of AJS in 1931, the Stevens’ family initials were reserved for AMC’s road racers [likely due to the disappearance of the 'Matchless' name from racing by the early 1920s - pd'o] while the company’s trials machines carried the names of both marques.
The most technically advanced AJS racer, the liquid-cooled, supercharged 500cc V-4 introduced in 1938, looked like a sure championship contender, but fell victim to the post-WW II ban on forced-air induction.In contrast, the normally-aspirated 350cc 7R single, first seen in 1948, was a winner right from the start, its affordable price and easy maintenance making it popular with private riders as the “Boy’s Racer".
Things changed in 1951, when the AMC race shop fitted a competition version of the company’s 500cc road-going twin into the 7R frame and entered the prototype, wearing Matchless badges, in that year’s Manx Grand Prix. A year later, the Matchless racer, now dubbed the G45, was back to win, leading from start to finish and setting new lap and race records. For 1953, the world’s “only multi-cylinder production racer” was part of the Matchless line-up. After several years’ campaigning, with modest results in the championship rounds but greater success on tracks in the Commonwealth countries, the G45 was replaced by the G50, a bored-out version of the 7R that came on the market in 1958. All told, perhaps 100 G45s were manufactured, some of them going to the works team, most sold to private racers seeking an alternative to the pricey and technically notchy Norton Manx.
Thus the standard history has it that AMC’s only postwar twin-cylinder production racer was a Matchless. Geoffrey Wood’s 1969 article for the American magazine includes an illustration of the G45 with an AJS-branded tank, but writes this off as a borrowed component from the 7R.
Recently, however, a variation on that theme has been sounded, lending confirmation to a story Alan Cathcart published in 1985 in Classic Bike ["Restoring the unique AJS 10R", Aug. 1985].
In 1954, at least three and possibly as many as five 500cc twin-cylinder racers were released by the AMC factory, all destined for South America. Designated the AJS 10R—a logical extension from the 350cc single-cylinder 7R—these unique machines were, of course, G45s wearing different livery.
The first tip about the elusive 10R racer came from Alan Cathcart, in the article already mentioned. A few years later, Roy Bacon provided further evidence in his "British Motorcycles of the 1940s and 1950s", which included a photograph (shown above) of an AMC race bike being loaded onto a plane. The wrappings carry a prominent AJS logo, but the caption beneath the photo reads, “Despite the packing, there is a Matchless G45 under there en route to Venezuela.”
According to Alan Cathcart’s report, the genesis of the 10R was in Caracas, not in London. AJS and Matchless were sold by separate dealers in Venezuela, rather than jointly as was sometimes the case in the UK and the US. The result was a good bit of competitive spirit that carried over to the racetrack, where in the early 1950s British bikes contested Italian makes like Moto Guzzi and Gilera. Much of the racing took place on public streets (closed off by the police), with competitors riding modified versions of factory-issued road bikes.
The well-known enthusiasm of President Marcos Pérez Jiménez (1952-58 see photo above) for motorsport encouraged local rivalries and rewarded risk-taking. In this freewheeling scene, any advantage that might be gained was not to be disregarded.
The Caracas importer for AJS was Julio César León, who was determined to keep his make at the front of the racing pack.When the G45 came on the market in 1953, León wanted the new racer, but only if it he could have it with AJS branding. After a year’s delay, in 1954 AMC obliged, “amazingly,” as Alan Cathcart put it. Five G45s were fitted with AJS tanks and timing cases and shipped, in AJS packing, to Venezuela. Entered in the race programs as AJSs, the bikes accomplished their purpose, keeping León’s riders in the battle for the national honors. They were raced, Cathcart wrote, until they were no longer competitive and were then retired. Only one had survived and was being restored to its original condition by a Caracas collector.
Neither Mick Walker’s scrupulously researched AJS and Matchless marque histories nor such other reliable sources as Cyril Ayton’s "A-Z Guide to British Motorcycles" and Mick Duckworth’s "Classic Racing Motorcycles" give any hint that—as Alan Cathcart cleverly phrased it—“a racing version of the AJS Model 20 twin” ever existed.
(AJS Model 20 roadster engine pictured)
Stories about this or that G45 have appeared in enthusiast magazines like Classic Bike and Classic Racer, especially when one of these veteran racers has been safely returned to its country of origin. But there has not been a feature on those one-off 10Rs that were shipped to South America in 1954.
In January 2008, Paul Mihalka, who now works for a BMW dealer in the US, posted a four-part memoir to an online riders’ site recalling his years as a young motorcycle racer in South America in the 1950s. Born in Hungary, Paul emigrated with his family to Venezuela after the war, where he learned Spanish by going to the movies and how to ride by hanging around motorcycle shops and race tracks.In 1953, Paul won his novice race on an AJS 350cc single.He then made a deal with the local Velocette dealer that enabled him to ride a much-modified 350cc MAC pushrod single in the national championship series. Engaging in spirited competition with local hero José Antonio (“El Negro”) Vivas, who was on an AJS, Mihalka won two races and finished second or third in six others, giving him the Venezuelan title. His success qualified him to compete in the South American Championship race in Lima, Peru. Running in the 350cc class against a field that included Swiss-born Theodore Roth on an Enfield Bullet and his nemesis El Negro on a race-modified AJS 16, Mihalka brought his Velocette home to first, no mean accomplishment in his first year of full-time competition.
(Paul Mihalka (Velocette) leads José Antonio 'El Negro' Vivas (AJS) in a 1953 race.)
The only cloud on the Venezuelan horizon was the appearance, toward the end of the 1953 season, of the AJS 7R, a production racer with an accumulating record of victories on British racecourses. The local AJS importer, Julio César León, had succeeded in persuading the championship organizers to open the competition to this new breed of machine .A national hero thanks to being the first Venezuelan to compete in an Olympics, in London in 1948 as a cyclist, León had plenty of political clout. The 7R quickly showed itself to be superior to the modified street bikes that until then had the racetracks to themselves. For the 1954 season, the team León was going to field looked to have the edge. Since the Velocette dealer for whom Mihalka raced also held the local Matchless concession, the intramural rivalry was intense.
Mihalka was now equipped with an overhead cam Velocette KTT, cobbled together from a worn-out European example brought back to life with parts from his previous year’s MAC. The KTT gave Mihalka a first and a second in the first two races of the series. He was then offered the opportunity to ride a brand new Gilera Saturno by the Venezuelan importer for Alfa Romeo and Lancia. Pre-war Gileras, especially the 500cc single-cylinder “Otto Bullonis,” were still competitive on South American tracks, and the Italian company’s multi-cylinder 500cc racers had carried Umberto Masetti to two world championships in 1950 and 1952 and Geoff Duke to another in 1953. Although it used a modified version of a 500cc single-cylinder road engine, the Saturno was light, nimble, and superbly put together. It had a broad power band, with plenty of low-end acceleration, and could top out at 120 mph, not quite up to a Manx but within striking distance of the 7R. In Mihalka’s description, “It handled like nothing else before. It was super light. Its Italian nickname was ‘la Piuma,’ the feather. . . . [It was] the perfect bike for the Venezuelan race tracks.” With his new mount and points already in the bag, Paul appeared set to repeat his championship.
(above; Gilera 'Piuma')
But Julio César León was not without resources. He had already pulled one rabbit out of the hat by getting the regulations changed to admit the 7R. Now he turned to AMC to provide him with a match for Mihalka’s Gilera.
Before the Saturno reached Caracas, León had taken shipment of three 500cc twin-cylinder racers from London. These were G45s, which AMC had transformed into AJSs so that León could enter them as part of his team. As Mihalka recalls, “They were in full AJS colors and trim, and the engines were stamped with a serial number that said AJS 10R.” If the bikes had arrived as G45s, to be re-branded in León’s garages, Mihalka was prepared to file a protest. Instead, he was invited to see the bikes unloaded, neutralizing his objections.
(Paul Mihalka on his Gilera Saturno leads 'El Negro' on an AJS in 1954.)
Few details are available on the races that followed. Despite Julio César León’s ingenuity, Mihalka won his second championship, with five firsts and a second. He recalls losing to a 10R in one race, but beating the AJSs in at least two others. They were quick, Mihalka admits, but they tended to break, a fault not unknown to other riders of the AMC racing twin (e-mail, April 2008). The fastest of the 10R riders was Pedro José Betancourt, who went on to become one of Venezuela’s most successful racers. Another of León’s riders, the German-born Lambert Danzer, also made something of a name for himself on the 10R. At the end of the 1954 season, Mihalka decided (as he puts it in his memoir) to get a real life. He retired from motorcycle racing and, using his skills as a draughtsman and engineer, went to work for IBM. What happened to the 10Rs is a mystery to him.
In the early 1980s, one of the AJS racers came to light when Caracas collector Gerald Römer discovered it in “a shady part of town in the hands of old time mechanics and street racers” (e-mail, July 2008). The bike still had its oversized fuel and oil tanks, alloy front fender, and racing brakes, but was missing the original engine. Instead, it carried a single-carburetor AJS road engine, possibly brought up to CSR specifications (hot cams, high compression pistons, different carb jet). In place of the Burman four-speed close-ratio gearbox that the racers used, an AMC transmission had been fitted. With these changes, the ex-racer would have been well down on speed, a deficit increased by the heavier weight of the road engine.
(timing side of Römer's machine)
The bike was not running when Römer bought it, and he could learn nothing of its history, although it had clearly been through the wars. By then few people remembered the AJS 10Rs. Most people thought the bike was a G45 that had been “locally modified,” as Römer puts it. This was the motorcycle that Alan Cathcart profiled in his 1985 story. Römer kept the bike for several years, intending to restore it to G45 specifications. In 1991 or 1992, he sold it, still with the road engine, and along with a 7R and a G50 that had belonged to Lambert Danzer, to a California buyer. Before that, Team Obsolete boss Rob Iannucci had come from the US to inspect the 10R but, failing to recognize it for what it was, had passed on the chance to add it to his collection of rare AJS racers.
(drive side of the M20-engined 10R)
James Philbrick, who administers the online G45 Register in the UK and perhaps knows more about the AMC racer than anyone else, has written that beyond Alan Cathcart’s 1985 article and one or two photographs, little evidence of the AJS 10R remains. Philbrick then adds a note that in 1953 AMC built a 10R racer for a Singer automobile dealer in Twickenham, Middlesex. This dealer sponsored a 7R rider in local races and, when the G45 became available, wanted one to complete his team—but only if he could have it as an AJS (e-mail, July 2008). So Julio César León may not have been the first, or the only, AJS vendor to exact his due from the London factory. For anyone trying to track down the pedigree of an AJS or Matchless motorcycle, the interchangeability of the two marques presents a challenge. With the racers, the odds are steeper. Bill Martin, who helped restore a G45 in New Zealand, notes that some of the bikes meant for sidecar racing were bored out to 600cc, so that a few “over-sized” G45 engines may be lurking somewhere, waiting for an advantageous moment to come on the auction block (e-mail, July 2008). For racers that were campaigned over a long stretch, with frequent repairs, on-the-spot parts swaps, and variations that individual riders may have insisted on, the challenge becomes more arduous. What the 10Rs that were shipped to Venezuela in the 1950s may have looked like twenty or thirty years later can best be appreciated by anyone who follows the “found in a barn” features in features in Classic Bike and The Classic Motorcycle. Unfortunately, none of those barns has been in Caracas.
(above; a sectioned drawing of a 10R/G45 engine)
For some time Gerald Römer has been trying to track down stories of a 10R that might still exist, hoping to replace the one he let go in the 1990s. His contacts include some ex-racers who competed during the 1950s, when Julio César León’s dealership made sure the AJS brand was well represented on the Venezuelan tracks. A couple of Römer’s leads appeared promising, even if they required him to re-visit those “shady” parts of town. But in a recent communication, the Caracas collector writes that the trail “went cold suddenly,” as it often does when stories about old racing motorcycles begin circulating decades after they last saw track action.
Even before Paul Mihalka published his memoir, bits and pieces of the 10R story were coming to the surface. In a 2005 issue of Classic Racer, British racer and journalist Bill Swallow raised the question of the G45’s clone, the AJS 10R. Several letters followed, one of which, from the US, reported that two-time world champion Umberto Masetti rode a Matchless G45 “disguised as an AJS” in a race in Valencia, Venezuela in 1957. According to the correspondent, Masetti was riding for a dealer who did not want his entrant mounted on a Matchless (“Letter from America”). Presumably this was none other than Julio César León, still looking for an edge on the Venezuelan marketplace for British bikes. Was Masetti’s bike one of the original 10Rs that had been shipped from London? In fact, a photograph of Masetti astride a 10R appeared in the British publication Motor Cycling in February 1958, with the caption noting that “the local AJS agent doesn’t deal in Matchlesses” (“Sports Gossip”). The magazine wondered how the AJS racer had impressed Masetti, given that by the time he rode it he had three years’ experience on the world-beating MV Agusta under his belt.
As elusive as the facts of the 10R story are photographs that prove the bike’s existence. Yet that is where the story might best be traced. In 2006, Paul Henshaw’s "Encyclopedia of the Motorcycle" included a photograph of a “1954 AJS 10R racing twin” Unfortunately, other than the caption, no information is provided. The photo itself looks to have been taken in the AMC works and includes what appear to be packing materials, raising the question whether the bike is one of those destined for South America. In December 2007, Paul Milhalka posted a photograph of former competitor Lambert Danzer on an online site, with the caption indicating that Danzer was riding a 7R (“Lambert Danzer”). One look at the photo suggests something else. The 7R uses a right side exhaust. Danzer’s bike has an exhaust exiting from the left side of the cylinder head, implying a matching right side pipe. Could the bike be one of the ultra-rare three-valve 7Rs, with which AJS won the junior TT in 1954? That would explain the second exhaust. There are stories that a three-valve 7R was raced in Venezuela in the 1950s. Alan Cathcart noted this in his 1985 report, and Paul Mihalka remembers a “triple-knocker” 7R when he was winning his championships.
(Although captioned as a 7R, Lambert Danzer is riding an AJS 10R in this photo. Photograph courtesy of Paul Milhalka)
But a closer look at the Danzer photograph indicates otherwise. There’s a rev counter drive coming off the left side crankcase, a mechanical improbability on the overhead cam three-valve 7R. On the AMC 500cc twin, the drive ran off the left end of the exhaust cam, as in the photo. So in all likelihood, Danzer, with the AJS logo on his helmet, is riding one of the 10Rs. The overall look of the bike, and especially what can be seen of the engine’s architecture, is that of AMC’s 500cc racing twin, and the way it is fitted out certainly does not betray a last minute conversion intended to fool the scrutineers.
('El Negro' Vivas on an AJS 10R in Caracas in 1954. Note the AJS timing cover.)
In July 2008 Venezuela’s motorsport press commemorated the fiftieth anniversary of the death of José Antonio Vivas. Lauded as “the first great idol of Venezuelan motorcycling,” Vivas died at age twenty-six after he crashed his BSA Gold Star on the Los Próceres track in Caracas. “El Negro” Vivas was better known for his hard-charging style and fierce determination to win than for his riding skill—there were lots of spills, recalls Paul Mihalka, who patterned his own technique on the ever-so-smooth six-time world champion Geoff Duke—but he was a favorite with the racing public. Penalties, suspensions, and frequent quarrels with racing officials added to Vivas’s popularity.
For the anniversary of El Negro’s death, his family contributed some photographs, not seen for years, of the hero in action. In two of them, he is riding an AMC racing twin in AJS colors, which has to be one of the 10Rs. Paul Mihalka says that José Antonio Vivas did not have use of a 10R when they were competing, and given his penchant for dropping bikes, it is entirely plausible that Julio César León kept the daredevil rider away from the precious twin-cylinder racers in their first couple of seasons. But Vivas did take the South American championship twice, in 1954 in the 350cc class and again in 1955 in the 500cc class. In the latter year, the race reports listed him as riding an AJS.
('El Negro' airborne on the AJS 10R at the 1955 Championship Race in Lima, Peru. These two courtesy of Octávio Estrada, from the family of José Antonio Vivas)
So it could be that, for the championship, León relented and gave his charismatic driver the chance to show his stuff on the “big” AJS. Like Paul Mihalka’s photograph of Lambert Danzer in action, the photos of El Negro are spot on, one of them right down to the marque-specific AJS timing case, more evidence that the 10R ran, challenged, and won on South American race tracks. To the surprise of AMC’s directors in London—if they were even paying attention—and their marketing strategists, it was an AJS “production” racing twin, not a Matchless, that took an international championship."