Ser­tum 250

Rare Ital­ian

Old Bike Australasia - - CONTENTS - Story and photos Jim Scaysbrook

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.

FAR LEFT An ad for the 500 Ser­tum an­nounc­ing the new sprung frame. The bear on a spring refers to the patented rear sus­pen­sion sys­tem.

MAIN Front brake uses cast iron hub; Typ­i­cally Ital­ian fric­tion dampers for rear sus­pen­sion.

Cat­a­logue im­age of the Ser­tum 250 “Coppa Re Im­per­a­tore” (Tro­phy King).

LEFT The 250 un­der restora­tion, and miss­ing its prized fuel tank.

LEFT White strip­ing breaks up the oth­er­wise black décor. ABOVE Replica bat­tery box was made by Gianni. Gor­geous pri­mary drive cast­ing and gen­er­ous finned sump. Stun­ning petrol tank with crown mo­tif. Fric­tion-damped girder front fork. Electrics are a com­bi­na­tion of Mag­netti Marelli and Bosch.

4-speed gear­box built in-unit with en­gine – un­com­mon in the ‘thir­ties. Tool box sits close to carb and pre­vents the use of any air fil­ter.

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