Sertum 250
Rare Italian
In Latin and certain Italian dialects, Sertum means ‘wreath’ or ‘garland’, (or perhaps ‘crown’) such as is awarded to victorious athletes. For a short time, the Sertum motorcycle, manufactured in Milan by Fausto Alberti, was victorious itself, given that it was referred to as one of the Pentarchia, or ‘Big Five’ in the industry, the others being Motor Guzzi, Gilera, Benelli and Bianchi. Quite illustrious company indeed. Yet by 1952, Sertum was gone, kaput, bancarotta. Alberti’s original business was the manufacture of precision instruments, but in 1922 he opened a new factory in Milan to build industrial engines, which were also adapted for use in small watercraft. The business flourished and with increased capital and confidence, Alberti began eyeing the motorcycle industry. This was no easy scene to break into, with the long-established marques already mentioned controlling the market and dominating the sporting sphere which generated such vital publicity. It was 1932 before Alberti took the plunge into the twowheeled world, calling his creation Sertum.
The first Sertum was a 175cc side valve single, the Utilitaria, with a 3-speed hand-change gearbox built in-unit with the engine, housed in a tubular steel rigid frame with pressed-steel girder front forks. Impeccably finished, the Sertum sold well enough to encourage the factory to stretch the engine first to 220cc and later 250cc, and a 120cc two-stroke (named the Batua and introduced in 1930) with a pressed-steel frame was also added. The Batua had a long model life, remaining in production until 1941, due to its affordability and reasonable performance. Weighing 80kg and producing 2.5hp, the little twostroke was good for around 65km/h, which was all that was needed to get to work and home again. By 1934 a 500cc side-valve single was also in the line-up, proudly presented in a glittering display at the Salon di Milano Show. Sertum were busy on a new cylinder head design, and this appeared around 1936 in 250cc form. Alberti was not convinced that an overhead valve design – costly to produce and maintain – was strictly necessary, but he had a string of customers willing to shell out their Lire, so the new design went into production alongside the existing models. With its vertical timing chest that resembled an R7/R10 AJS, the new 250 was often mistaken for an overhead camshaft design. Alberti was full of ideas and in 1935 announced production of what he termed “the utility passenger car” – a cobby three wheeler (two at the front, one in the rear) using the 250cc side-valve engine but with seating for only one adult. Weather protection, it appeared, was the sole advantage over the motorcycles. In 1939, the all-new side-valve 500 twin – the VL Bicilindrica – was announced; available as a solo or a catalogued sidecar outfit. But then along came the war and like every industry in Italy, Officine Meccaniche Fausto Alberti was switched to the war effort. Sertum’s contribution was a military version of the 500cc side-valve single – the MCM500 – which quickly gained a reputation for its robustness and reliability. Until 1941, the civilian range was continued, albeit in truncated form, with the Butua now in 175cc four-stroke guise and the power up to a healthy 6.5hp with a top speed of 80km/h. Although motorcycle sport was necessarily curtailed, Sertum had enjoyed good results up to this point, competing with distinction in the long distance open roads events like the Milano-Taranto and especially the prestigious International Six Day Trial. In the 1938 ISDT held in Llandrindod, Wales, Sertum riders scooped no fewer than five Gold Medals. In the 1938 sales year, Sertum, together with Parilla, Bianchi, Moto Guzzi and Gilera, accounted for 97.4% of all motorcycle registrations in Italy. With the war finally over, Sertum struggled back into civilian production with a range that included 250 and 500cc singles and the 500cc parallel twin, all available with either side valves or overhead valves. The ohv 250 in particular was up-rated, now producing 12hp at 5,600 rpm with an impressive
top speed of 120km/h, and a 4-speed foot-change gearbox. Using a competition version of this model, the factory entered the 1949 ISDT in Czechoslovakia and annexed another three Gold Medals. Clearly however, the range needed up dating and in 1950 Sertum responded with two new offerings; a new 4-speed overhead valve 250 named the Ghibli and a 500 called the Maestrale, which in reality was the old parallel twin with a few tweaks. The new 250 was quite a sleek machine with light alloy rims, with the push rod tubes formed within the cylinder and cylinder head castings. A fourspeed gearbox was built in-unit with the engine. Bore and stoke were 66mm x 73mm, with magneto ignition, gear-driven on the front of the engine. The 500 twin, with the same 66mm x 73mm bore and stroke as the 250, had a single castings for the iron block and the alloy cylinder head, a single camshaft at the front of the cylinder and twin carburettors, one on each side. Ignition was by coil, with the distributor driven by the timing gear on the right side of the engine. In standard Sertum practice, pressed-steel girder forks were used, with swinging arm rear suspension using a leaf spring under the engine controlled by friction dampers. But the model upon which the company staked its future was entirely different. This 122cc two-stroke single used a four-speed gearbox housed in a pressed steel frame, but it faced stiff competition from similar models from a number of rival manufacturers, and never went into volume production. The factory used the basic design to produce what turned out to be the very last Sertum; an ohv 4-speed 250 in a pressed-steel frame, named the Monotubo.
The factory itself was, by 1951, in dire financial straits, with the traditional motorcycle industry under threat from the emerging moped and motor scooter creations, as well as light cars. The straw that broke Sertum’s back came when it dispatched a large delivery of motorcycles to Argentina, only for the recipient to declare bankruptcy and have the entire shipment seized by creditors. There was nothing for Sertum to do but follow suit. The liquidators were called in and the assets sold, and by the end of 1952 Sertum, once part of Italy’s motorcycling elite, was no more.
Sertums in the city
More than sixty years after the last Sertum was produced, the marque is scarcely remembered, even in Italy. Yet this was no backyard show; a quality product that deserved better than its twenty years of existence. And if the Sertum is rare in Italy, it is practically non-existent in Australia, except for two superb examples in Adelaide. Both these bikes are owned by Gianni Minisini, who was born in Udine in northern Italy. Gianni completed the restoration of the 500 around 6 years ago, but the 250 took a little longer and has only recently been declared ‘finished’. The side-valve 250 VL was developed from the successful 175 and for 1937 received Sertum’s telaio elastico, or sprung frame, with tubular steel girder forks up front and the company’s patented swinging fork rear suspension, with tubular steel arms on each side controlled by friction dampers. Springing at the rear is in in Moto Guzzi fashion, with a linkage to a leaf spring that sits vertically behind the central frame down-tube. Post-war versions used a revised front fork with pressed steel blades instead of tubes, a production method carried throughout the bike, with the swinging arm and rear sub frame all produced in pressed steel. This makeover added 22 kg to the previously svelte machine. The remainder of the frame itself is conventional, with a single front down-tube connection to the front of the wet-sump engine, which forms part of the chassis. Gianni’s 250 Sertum, finished in sombre black with white striping, is an altogether more delicate and svelte machine than the robust 500 in its strident red decor. There is certainly a family resemblance in the engine/gearbox department, and while the post war 500’s foot-change is an obvious add-on from the previous hand-change set up, the pre-war 250 has the foot-change mechanism designed as an integral part – quite unusual for the 1930s in Italy. The 250 would have been completed much sooner had it not been for a worrying set back. “I sent the petrol tank away to be painted,” explains Gianni, “but when nothing had happened for a while I investigated and found the company had gone broke. It took me a year to get the tank back and then I had to have it painted by someone else.”
Like most Italian motorcycles of the period, the petrol tank is the crowning jewel of the machine. Finished in deep chromium plate with white and black highlights, the motif depicts a crown, for Sertum also loosely translates as corona or royal headdress.