Meet a one-off bike that has survived more near-misses, more owners and more engines than any other!
Words and photos by Oli Hulme
Around the nation there are still sheds and barns holding motorcycling gold. There’s a barn near me with a low mileage T150 Trident and a spotless Daytona rubbing handlebars with a real Indian Enfield (an official rebadged 1950s Meteor complete with a fringed saddle) that doesn’t run and which the owner won’t part with. There’s a large shed with 50 or more Velocettes in it, too. With a Morini that’s well into its third decade as a restoration project, I’m in no position to question such behaviour. Sometimes, those items of gold are more exotic than others, and others are just fascinating, such as this remarkable creation. It has a long and intriguing heritage stretching back to the 1960s, has had the hands of motorcycling’s more creative geniuses pass over it, and still gets the occasional outing. Ladies and gentlemen, I give you: The Conundrum.
Conundrum is but one of the names this quirky special has run under; it has also been identified as part MZ, is registered as a Sunbeam, and been named the Tweaky Beast.
The story begins in the mid-1960s, though indeed it may date back even further as the frame of the motorcycle is of uncertain origin, possibly going back to the 1950s.
In early 1965, John Griffith – journalist, TT Racer, one-time VMCC president and later founder of the original Stanford Hall Motorcycle Museum – sold an old racing frame from an MZ that he had probably bought from TT racer Norman Webb to fellow vintage racer Bert Milnes. Bert paid £60 for the frame, which was quite a lot of money, so he must have seen something special in the curious lightweight.
The frame was a replica of a Norton Featherbed, redesigned for a lightweight engine using slender 24mm tubing and even thinner 18mm tubes for the rear bolt-on subframe.
The frame, stamped as number L101, was fitted with the most unlikely of engines for a race bike, the powerplant from a 250cc Sunbeam scooter, originally a 10bhp four-stroke twin, also fitted to the Triumph Tigress. That ran with an enclosed chain but for these purposes was converted to conventional chain drive and fitted with a big 1/16in Amal Monobloc carb and a high-level ‘Burgess’-style silencer.
The use of the Sunbeam engine allowed Bert to register the resulting creation as a Sunbeam and it was issued with a proper registration number. They were different times.
The bike was interesting enough to have been photographed by Motorcycle Sport magazine at the 1965 Manx GP, having been ridden there by Bert’s son, Robert.
Shortly afterwards, a stay was brazed to the headstock to allow the fitting of a beaten aluminium fairing, and this was bolted to the hand-made tank, which already included arm rests, allowing the rider to get as low over the tank as possible.
In 1966, the future Bantam racing and ignition creating genius, a young Rex Caunt, was working at Bert’s shop as a mechanic and bought the bike for £45, giving it the Tweaky Beast nickname. He braced the swingarm, fitted a BTH racing magneto, and painted the frame blue and green.
He tried to start racing on it, but it failed scrutineering because it didn’t have ballend levers. He instead bought a Moto Rumi, on which he started a successful racing career, and sold the Sunbeam on without its engine in 1969.
It next broke cover in 1973 at a hill climb in the north of England and eventually ended up in Goosnargh, near Preston, missing the engine, fairing, log book and registration number. It was sold again, this time for £10, to a scrap metal dealer and Velocette fan called Bernard Seed, who moved to the Isle of Man in 1980. The bike seems to have had a magnetic link to the island.
The frame was then proposed as the home for a Tiger Cub engine, a plan that never came to fruition, and it was hawked around Isle of Man for most of the 1980s, but nobody wanted to buy it. It ended up in a shed owned by a friend of Bernard’s. It was eventually sent to another scrap dealer when the shed’s owner died, and his widow, fed up with people trying to take advantage of her in the wake of her husband’s death, insisted she would not see it sold for use as a motorcycle frame, so it was partly crushed.
In 1998, a couple of Manx bike fans found the damaged frame in a scrapyard, dragged it out of a pile and bought it – the day before it was due to be finally crushed. They subsequently decided that it was too far gone to do much with but kept it, the way you do. Two years later the rolling chassis was offered to Grahame Williams, of Birmingham, for £50. It was described as a Tiger Cub Special and he bought it unseen.
By now, the frame looked even more beyond saving, but it was clear to Grahame and his son Andy that while what they had might look like scrap, it was something rather special. Grahame gave the chassis to Andy and he got to work. As a dedicated archivist, Andy started to piece together the bike’s history as he pieced together the bike. He contacted Old Bike Mart and an article was published, without any info coming forward. Andy then joined the VMCC and spoke to its Isle of Man section chairman. This resulted in a phone call from Bernard, who revealed he was still the official owner of the machine but was happy to hear it was being rebuilt and gave Andy ownership. Andy spotted an old Motor Cycle News article published decades earlier referring to Rex Caunt, who was by now building racing ignition systems, as the possible owner of the bike. Andy contacted Rex and got a call back. Andy said: “His first words were, ‘you’ve got my Tweaky Beast’. He had wondered what had become of Tweaky and was pleased it had survived. Within a few weeks, I took it up to his workshop so he could see it again.”
The original registration document was then found in the Leicester County Archives, and a further lucky find was uncovered on a stall at Red Marley Hill Climb, a copy of Motorcycle Sport from 1965 that contained a photograph of the bike. Andy now knew what the bike looked like originally.
The frame repair was farmed out to a racing and engineering workshop, but Andy said the job done was so poorly that his heart went out of the rebuild for nearly another decade.
In early 2015, a chance meeting with replica Brough Superior frame maker Caleb Whitcombe, while Andy was carrying out an MoT on Caleb’s Ducati, began to move things forward. Caleb checked the frame on his jig, advising Andy that it was pretty much scrap and it would be better to make a replica of it, but that the subframe and swingarm were thought to be repairable.
Andy asked him to repair the forks while he decided what to do next. The top yoke was changed to a split clamp, the fork stanchions came from a Puch VZ50, and other parts were sourced from the parts bin – BSA Bantam gaiters, Puch headlight and speedo, Amal grips and a Doherty throttle, MZ250 levers, and the Smiths rev counter was mounted on a repurposed tax disc holder.
For the frame, an expert bender of tubes managed to reproduce the complex bends, and the steering head angle is the same as a Featherbed. The footrest brackets had twin height settings, the rear sets were handmade, and the rear brake lever is swappable for a right or left-hand orientation. The original swingarm was straightened out, as was the rear subframe. There were Honda CB500 bits in there too, CB500s being Andy’s other passion.
The original rear guard was repaired and paired with a 1970s Yamaha offering at the front, and there are Sunbeam tank badges, harking back to the Conundrum’s origins.
To power the reborn beastie, Andy used a Ducati Monza Junior 160 motor found on eBay. Inevitably, when it arrived, Andy said it turned out to be ‘full of swarf,’ with a conrod that had been welded up on the top end, probably due a seizure.
Andy managed to get tuning legend Pip Higham to rebuild the engine, with lots of tuning mods. These included a NOS con rod, new bearings and shims, a high-delivery oil pump, a 62mm Borgo piston, and the barrel was shortened to increase compression.
There were Kawasaki valves, opened-up ports, and the Ducati hairpin springs were converted to Suzuki GSX-R coil springs and GS1000 top caps. An Amal 24mm carb was fitted to a one-off manifold and the kickstart was made from a mix of Ducati, Puch and Yamaha TZR parts.
In November 2017, a coil and battery from a Honda CB500 were fitted. After a push start, the Conundrum fired and rolled under its own power for the first time since 1969.
To make it useable, an Electrex alternator kit was fitted, along with a Dyna coil and a tiny 2.5ah battery. A home-brewed exhaust was made from two Ducati 160 downpipes and a reverse cone megaphone.
There was then a long hiatus as Andy tried to get the bike registered. Despite the wealth of information he had amassed, it took two years to get a registration document, and even then the DVLA denied him the opportunity to use the original registration number, instead providing an age-related plate, though it did agree that it was a Sunbeam, despite the only Sunbeam parts by now being the Indian-made replica tank badges.
With all the work done, it was time to try it and iron out any bugs. “It was quite twitchy,” said Andy, so mods were made to the steering head, with offset frame inserts for the steering head races to sit in, making it very stable in a straight line. The final drive gearing was too low, so a 48-tooth rear sprocket was fitted. An irritating ignition fault saw Andy pull the wiring apart trying to find it, as well the replacement of the coil and kill switch, until the source of the fault was discovered to be a brand-new ignition switch – as always seems to be the case. A more powerful battery was fitted, some modifications were made to the points back plate, and a bicycle speedometer was fitted too. The gearbox had to be rebuilt, and a 26mm ZSTRP flat-side Keihin copy carburettor from China was fitted, which had jetting that was much easier to set up than the Amal.
Andy said: “The handling is very precise; the suspension is firm but comfortable and the brakes are really good. The riding position is set up for me, and it goes around corners like it’s on rails.”
There may be changes in the future, too. Andy added: “I’ve got a 4T Villiers to maybe fit in and twin Amal concentric carbs and race pipes to go too. Or I may sell it – I’ve not decided yet. It’s a love-hate relationship after 24 years.”
