From our Old Bike Archives – Issue 74 – first published in 2018.
Story: Jim Scaysbrook • Photos: John Rettig
Spectators marvelling at the handsome overhead camshaft AJS at the 2016 Ross Rally could be forgiven for thinking this was a lightly-used example of a ‘thirties thoroughbred, maintained in meticulous condition by a series of careful owners.
In reality, this was a grizzled veteran of decades of competition on beaches, road circuits, hill climbs, scrambles and as a record-breaker, that had been blown up, all but lost, and saved from the grave by a series of enthusiasts who were passionate about the preservation of machines with a strong Tasmanian connection. They don’t come any stronger than this old warrior.
The 500cc R10 was the big brother to the 350cc R7, the chain-driven overhead camshaft AJS that superseded the famous and highly successful ‘Big Port’ overhead valve model. It was a time when ‘camshaft’ engine designs were all the rage, with Velocette and Norton already hard at work on their own designs by the time the AJS version saw the light of day in late 1926. AJS were aghast that their previously all-conquering 350 OHV model had been beaten in the 1926 Junior TT by Alec Bennett’s OHC Velocette, so AJS Chief Designer Phil Walker was charged with the task of producing AJS’s contender in the ‘cammy’ stakes. What he produced became one of the most successful racing designs ever – one that evolved into the post-war 7R and eventually the 500cc G50 Matchless.
Unlike the other British designs that used bevel drive to the overhead camshaft, Walker employed a chain drive with the chain tensioned by a slipper tensioner known as the Weller device, which had been used in the racing Aston Martin car engines, and in numerous aero engines. This chain was enclosed in a rather handsome aluminium casing, which became a feature of the AJS/Matchless motors, particularly when it was constructed in magnesium and painted gold to prevent oxidisation. Outside the case, an oil pump was fitted to feed and scavenge the dry sump engine which employed a caged roller big end bearing.
In the hands of ace rider Jimmy Simpson, the new engine (installed in the old ‘Big Port’ frame) was immediately successful, taking out the Swiss, Belgian and European Grands Prix in 1927. By 1929, the whole package had been refined with a new frame and was offered in limited numbers to private entrants, and as well as the original 350cc model, a new 498cc version appeared. A single 250cc version was also built and ironically achieved the first major success for the new design, winning the 1930 Lightweight TT ridden by the legendary Jimmie Guthrie.
But while this overhead-camshaft progress was proceeding apace in the AJS race shop, things were not so rosy for the venerable Wolverhampton firm itself, which collapsed in 1931, and was taken over by the Colliers brothers Matchless concern, eventually becoming Associated Motor Cycles (AMC). Colliers were not seriously keen on racing, so for several years the OHC AJS models lay dormant, until 1933, when it was substantially redesigned, including moving the magneto from the front of the engine to the rear where it sat under the carburettor. The oil pump also moved from the crankshaft level to the top of the engine. A completely new frame was also designed and produced. Much later, in 1937, a further redesign saw the 350/500 models appear with new double-loop frame and Burman gearboxes – the true forerunners of the post was 7R/G50 models.
A long way from Wolverhampton
Although exactly how it arrived there is unknown, a 498cc R10 AJS made its way to Tasmania in the early ‘thirties, where it was modified for race use by Frank Hallam of Launceston, who later worked for Repco. Frank modified the AJS by fitting a four-speed gearbox, before selling the bike to fellow Launceston resident Ev Sadlier. In Ev’s hands the AJS appeared in solo form in hill climbs, beach races, speed trials and record attempts over the next decade. Around 1949, Sadlier sold the AJS to Archie Andrews to fund the purchase of a new Triumph Speed Twin. Thereafter the bike passed to Ken Holmes and eventually, with a blown up engine, to Geoff Martin.
“I purchased this bike in a blown up condition, having thrown a rod”, said Martin in a letter to OBA a few years back. “I eventually finished this project and used the bike in a couple of hill climbs and acceleration tests. I found it was unpleasant to handle and the vibration was undesirable. Previous owners had also found this problem. Almost every bolt was drilled and wired to deal with this by previous owners, so I did another rebuild and read all about balance. I fitted a Manx Norton piston, which improved it slightly. The flywheels had been turned down, which was undesirable, so I turned two steel bands round them and shrunk them on and repolished them so they were now back to original size. It was now beautifully smooth and revved much better, and I started to get a few wins against much better bikes.”
Martin raced the AJS in both solo and sidecar form, achieving some commendable results. The now-venerable engine was soon transplanted into a later model AJS swinging arm frame, still using the original R10 girder forks, and with a sidecar attached. The original frame and running gear were stored at the home of Launceston AJS agent Trevor Jowett, who also owned the famous 1000cc v-twin OHC AJS record breaker at the time. Martin further modified the old R10 engine with cam profiles copied from the v-twin, and fitted an Amal GP carburettor. In this form, Martin scored second place behind Bernie Mack’s Norton at the Australian TT held at Longford, Tasmania in 1953. For the next ten or so years, Martin raced the AJS all over Tasmania until it eventually blew up at Longford in 1958, completely destroying the crankcases. This was a major setback for Geoff, and he even penned a letter in 1960 to Associated Motorcycles in London, requesting help with parts and information. The factory replied, offering their congratulations on the success achieved with “this very old type engine,” but suggesting only that Geoff write a letter to the editors of the British weekly magazines, seeking help from readers. So it was back to seeking a local solution, and with the help of Trevor Jowett, the owner of a second R10 AJS at Mole Creek in Tasmania was contacted and he agreed to sell his bike for fifty pounds. The owner actually rode it from Mole Creek to Geoff Martin’s son Graeme at his service station in Launceston, collected his fifty quid, and headed off home.
The project of amalgamating the two bikes into one fell to Graeme, but with a business to run and a young family, progress was slow and both bikes were eventually sold to Keith Bingham in Hobart and soon after to Dick Plant, who disposed of the later AJS chassis (to the local tip) and began restoring the ‘Mole Creek’ R10 into its original form. Unfortunately, he passed away in 1999 before this could be completed. During this period, well known Melbourne identity, the late Jack Nelson had managed to extricate the original R10 chassis, which was still languishing, engine-less, behind Trevor Jowett’s shed in Launceston. Nelson collected the chassis and a quantity of well-used engine parts, and collaborated with his good friend Ron Loft, also of Melbourne, who by that stage had bought the ‘Mole Creek’ R10 from Plant’s estate. Jack eventually discovered a set of R10 crankcases in Victoria and a rebuild was begun, but this soon stalled and the R10 languished in Jack’s spacious shed in Romsey, north of Melbourne, where it had lots of Rudge and Douglas motorcycles for company.
In 2004, Tasmanian Casey Overeem spotted the AJS while visiting Jack and immediately recognised it as the ex-Ev Sadlier model. After some negotiations, the AJS was swapped for a quantity of Rudge parts and shipped back across Bass Strait. Overeem had plans to restore the AJS to its former glory but was heavily committed to his business, so he agreed to sell the project to John Rettig – a man who has owned a long line of desirable motorcycles over the years. John set about rectifying the situation once and for all, and the much-travelled and much-molested AJS R10 made its restored debut at the 2016 Ross Rally in central Tasmania where it attracted considerable interest.
If only this bike could talk, it would surely have a tale or two to relate from the time it left chilly Wolverhampton for a life in the colonies. Through numerous blow-ups and endless modifications, it is a credit to the perseverance of several people, most recently John Rettig, that the old warrior is now, finally and hopefully permanently, back in its original form – another motorcycle with a chapter all of its own in Tasmania’s illustrious heritage of motorcycling.
