AERMACCHI CHIMERA................................

Sleek and su­per-snazzy, this Latin light­weight stole the lime­light at its launch. Which just goes to show that the mo­tor­cy­cle press knows ab­so­lutely noth­ing about what the pub­lic wants to buy. Rowena Hosea­son finds it has con­sid­er­able clas­sic ku­dos, howev

Real Classic - - What Lies Within -

Sleek and su­per-snazzy, this Latin light­weight stole the lime­light at its launch. Which just goes to show that the mo­tor­cy­cle press knows ab­so­lutely noth­ing about what the pub­lic wants to buy. Rowena Hosea­son finds it has con­sid­er­able clas­sic ku­dos, how­ever

‘These days it’s con­sid­ered mag­nif­i­cent,’ says owner Basil Keir, who might be a tiny lit­tle bit bi­ased when it comes to the Aermacchi Chimera. He loves its ‘stun­ning looks and fu­tur­is­tic styling’ but freelyy ad­mits that ‘it wasn’t ac­cept­edp byy the Ital­ian pub­lic’ back in the 1950s. Ma­chines like the Chimera still di­vide opin­ion to­day but there are enough en­thu­si­asts around to en­sure that any which come on the mar­ket are rapidly snapped up. In­deed, Basil paid… well, ‘too much’ for his 175. But most clas­sic bike en­thu­si­asts wouldn’t give you tup­pence for such an un­con­ven­tional con­trap­tion – which is a shame, be­cause there’s some solid and in­no­va­tive en­gi­neer­ing lurk­ing un­der­neath that jet-in­spired styling.

The Chimera came in two ca­pac­i­ties and was built in tiny num­bers be­tween 1956 and ’64. There were less than 300 man­u­fac­tured, just 119 175s and 177 250s. Which means that you’re more likely to fall over an ohv Brough Su­pe­rior SS100 than you are an Aermacchi Chimera. Talk about rare!

Along with many Euro­pean mo­tor­cy­cle man­u­fac­tur­ers, Aermacchi con­cen­trated on light­weight com­muter ma­chines to get them into the post-war civil­ian game. They’d been build­ing air­craft for four decades and needed a non-mil­i­tary

mar­ket for their en­gi­neer­ing ex­per­tise. Two-wheel­ers looked like a solid bet in the aus­ter­ity-driven post-war econ­omy, and their first two-stroke semi-scooter ar­rived in 1951 af­ter one of Lino Tonti’s de­signs caught the man­age­ment’s eye at a trade fair.

Tonti didn’t stick around at Aermacchi for long,g, and the head de­signer’sg desk was soon filled by Al­fredo Bianc­chi (who was also re­spon­si­ble for the As­to­ria aand the Par­illa). The Chimera was Bianchi’s fi­first project for Aermacchi and it was also the firm’s first fourstroke mo­tor­cy­cle. While Bi­aanchi han­dled the me­chan­i­cals, stylist Mario RRev­elli at­tempted to unite form and func­tion, aim­ing for a ‘per­fect fu­sion of in­dus­trial ne­ces­sity and aes­thetic grace’ (that’s a verry loose trans­la­tion from a con­tem­po­rary Ital­iann in­ter­view). Rev­elli, an ex-GP bike racer and car stylist, pro­duced a sketch of his ideeal mo­tor­cy­cle, and Bianchi built a bike around that con­cept.

The fin­ished ma­chine cer­rtainly wowed the crowds at Mi­lan. Pe­riod pub­bli­ca­tions ex­tolled its smooth, flow­ing de­sign aand con­sid­ered the Chimera to be the ‘peakk of en­gi­neer­ing el­e­gance.’ The Mo­tor Cy­cle ppos­i­tively gushed about how ‘the dar­ing origi­inal­ity of line and construction are re­fresh­hingly free from con­ven­tional ideas.’

Un­der­neath the strik­ing eex­te­rior, how­ever, lurked an al­most een­tirely ortho­dox ohv mo­tor. The 60mm by 611mm, unit construction en­gine used vver­ti­cally-split, alu­minium al­loy crankcases which pro­vided part of the vis­ual im­pact; a built-up, roller bear­ing big end, cast iron bar­rel and an alu­minium cylin­der head. Su­per-sport­sters of the time were equipped with over­head cam en­gines, but Bianchi opted for a pushrod de­sign – cheaper and eas­ier to build, sim­pler to main­tain and more durable for ev­ery­day du­ties.

Bianchi used hel­i­cal gears to trans­fer the pri­mary drive – no prob­lem for an in­dus­trial aero­nau­ti­cal man­u­fac­turer, fa­mil­iar with work­ing to ex­tremely tight tol­er­ances and tooled up to cut pre­ci­sion gears. Then power was con­veyed through a wet, multi-plate clutch to the chain fi­nal drive. The kick­start was sit­u­ated on the left while a right-side, heel-and-toe lever se­lected ra­tios in the four­speed gear­box.

The com­pact mo­tor was hor­i­zon­tally in­clined – es­tab­lish­ing a fu­ture hall­mark of the mar­que – which meant that the cylin­der head faced for­wards. ‘ Two of the big­gest prob­lems fac­ing the de­signer of an en­closed model con­cern en­gine cool­ing and ac­ces­si­bil­ity,’ com­mented The Mo­tor Cy­cle. ‘Both have been ex­pertly tack­led… cool­ing air en­ters the open front of the die-cast alu­minium al­loy en­gine cowls and im­pinges di­rectly on the cylin­der head. No amount of hard rid­ing pro­duced the slight­est symp­tom of over­heat­ing.’

The en­gine lay­out also car­ried the mo­tor­cy­cle’s mass as low as pos­si­ble to en­hance the Chimera’s han­dling. This ap­pears to have been suc­cess­ful, as own­ers re­port that the Chimera cor­ners like it’s a lit­tle rocket on rails. The styling hides an­other of its as­sets; an early form of hy­drauli­cally-damped monoshock sus­pen­sion with a sin­gle rear spring tucked away un­der the sad­dle. This, at a time when many mo­tor­cy­cle man­u­fac­tur­ers were still sell­ing their lightweights with plunger rear sus­pen­sion – or no rear sus­pen­sion at all! Ap­par­ently, Aermacchi tested their chas­sis for months dur­ing the model’s de­vel­op­ment to en­sure that the frame would with­stand the rigours of reg­u­lar rid­ing. Mo­tor Cy­cling re­ported that ‘huge cams pumped the sus­pen­sion, and other lit­tle de­vices ap­plied stress at such points as the steer­ing head. It brought out ini­tial weak­nesses in the rear sus­pen­sion spring but I was as­sured that at no other time had the frame it­self failed.’ As con­firmed by owner Basil: ‘ The rear sus­pen­sion is quite ad­vanced for its day and gives it nice han­dling com­pared with Bri­tish con­tem­po­raries of sim­i­lar size.’ The front end ap­pears to be fairly con­ven­tional with a pair of tele­scopic forks, although all the con­trol ca­bles and the han­dle­bars them­selves are hid­den from sight by a quickly-de­tach­able na­celle (easy for the home me­chanic to re­move for ac­cess to ad­just the steer­ing head bear­ings). But the heav­ily-valanced front mud­guard is an­chored to the lower yoke rather than to the 17-inch front wheel, so the wheel moves to­wards the guard rather than the pair mov­ing in tan­dem. This was odd enough to dis­cour­age

some buy­ers at the time, who didn’t like the gap be­tween the wheel and the guard – nec­es­sary for soak­ing up bad bumps on Ital­ian by­ways.

And if the front end ar­range­ment dis­suaded the ca­sual browser, then you can bet they weren’t at all in­spired by Rev­elli’s jet-in­spired styling job. Like the Ariel Leader (and most scoot­ers) it at­tempted to ‘clean up’ the mo­tor­cy­cle’s ap­pear­ance. Ev­ery­thing had to be un­clut­tered and sleekly sculp­tured. All the un­tidy me­chan­i­cal as­pects – ca­bles, oil­ways, fuel pipes, drive chain and even elec­tri­cal equip­ment – had to be hid­den from sight be­hind the sweep­ing pressed-steel en­clo­sures.

This might seem to be a rad­i­cal no­tion, one which con­flicts with the un­der­stand­ing that most mo­tor­cy­clists are in­ter­ested in the en­gi­neer­ing that un­der­pins their form of trans­port. Clas­sic rid­ers in par­tic­u­lar tend to like look­ing at their en­gines. But if in the 1950s mo­tor­cy­cles were to be­come mass trans­port, so the rea­son­ing went, then they needed to be less me­chan­i­cally in­tim­i­dat­ing. And a lot less oily.

Hence the fash­ion for full en­clo­sures as adopted by most Bri­tish man­u­fac­tur­ers, and Ariel’s full-scale pur­suit of a main­stream mar­ket that never de­vel­oped.

The Leader and its ilk were left high and dry… well, un­til three decades later when an­other gen­er­a­tion of de­sign­ers would do this all over again with the Du­cati Paso, Morini Dart and Honda’s CBR600F. They also at­tracted a fair amount of flak from mo­tor­cy­cle en­thu­si­asts…

Mind you, the Chimera al­ways had a solid core of ad­mir­ers. It still at­tracted favourable com­ments in the mid-1980s when Cyril Ay­ton, editor of Mo­tor­cy­cle Sport, was sur­prised to note that the Chimera’s body­work ‘con­trived to look rather el­e­gant… sleek and gen­tle­manly.’

You can cer­tainly see the jet-en­gine in­spi­ra­tion in the way the two cream cen­tre-sec­tions meet un­der the petrol tank at the front of the ma­chine to en­close the horn. The red trim around the alu­minium en­gine cas­ings def­i­nitely brings a sense of the stream­liner. Think De Hav­il­land Comet and you prob­a­bly get the sense of what Aermacchi were aim­ing for – mi­nus the metal fa­tigue, of course.

Nor was the Chimera an im­prac­ti­cal propo­si­tion. The body­work, like the in­stru­ment na­celle, was de­signed to be rapidly re­moved for reg­u­lar main­te­nance. Own­ers of a fully-clad Nor­ton Dom­i­na­tor Deluxe might won­der how on earth they could flood the carb, but on the Chimera all the nec­es­sary open­ings and aper­tures were de­signed in to the pressed steel pan­els, which also housed a three-way petrol tap and a lock­able tool­box.

The Aermacchi’s spark plug was po­si­tioned to­wards the front of the com­bus­tion cham­ber at an an­gle, so it could be ex­tracted us­ing the long span­ner sup­plied with­out re­mov­ing the en­gine cowl. Like­wise, you didn’t need to strip off the body­work to get at the en­gine oil dip­stick or con­tact breaker points. The stan­dard equip­ment even in­cluded a type pump.

The Chimera could also clip along at a rea­son­able rate for a mo­tor­cy­cle which car­ried a lot of pressed steel around with it. The 175 started out with an 18mm Dell’Orto carb; the 250 ended up with a 22mm item.

The 13bhp pro­duced by the 175 en­gine gave it an ab­so­lute top whack of 68mph and the abil­ity to cruise at 60 for ex­tended pe­ri­ods. The 250 ver­sion, equipped with dif­fer­ent gear ra­tios but other­wise much the same as the 175, could just about touch 75mph – which put it ahead of Ariel’s two-stroke Leader. In part that’s be­cause the Chimera weighed around 25lb less than the Leader. And once you stripped away more of the mass, as Aermacchi did in the years that fol­lowed, the 175 and 250 en­gines more than proved their met­tle as light­weight rac­ers. When it be­came ob­vi­ous that cus­tomers weren’t stam­ped­ing to the show­rooms, Aermacchi re-worked the Chimera to pro­duce a range of more con­ven­tion­al­look­ing dual-shock road­sters with clas­sic café racer styling. The 18bhp Ala Verde 250 ran slightly higher com­pres­sion than the Chimera, and was equipped with a dual, 8-inch front brake to match its 80mph per­for­mance. Even so, Aermacchi’s ven­ture into mo­tor­cy­cle pro­duc­tion didn’t bring the com­mer­cial suc­cess they’d sought. En­ter Har­leyDavid­son who bought half of Aermacchi in 1960 – and so the spirit of the Chimera lived on in the Sprint 250 and then 350. A later de­vel­op­ment even en­joyed suc­cess on the Isle of Man, fin­ish­ing sec­ond in the Ju­nior TT in 1969 and ’70.

The Chimera con­tin­ues to wow a cer­tain seg­ment of the clas­sic world, and its prices re­flect its rar­ity. While £3000 will buy you a fully re­stored Ariel Leader, that’s the low­est pos­si­ble price you’ll pay for a barn-find Chimera (if such a thing ac­tu­ally ex­ists), miss­ing some com­po­nents and in need of a com­plete over­haul. En­gine and an­cil­lary spares aren’t hard to come by, but you’ll need a body­work whiz to bring its pan­elling back to per­fec­tion. Or you can scour the sales – when an im­mac­u­late 1958 175 was of­fered at an auc­tion in Lon­don last year, the ask­ing price was £15,000. Please don’t choke on your chips.

Look­ing at the pho­tos of this imag­i­na­tive ex­per­i­ment, I can’t help won­der­ing where we might be to­day if yes­ter­day’s mo­tor­cy­clists had em­braced such a bold vi­sion of tomorrow. What would our 21st cen­tury mo­tor­cy­cle be like, if the in­no­va­tors and engi­neers of the 1950s had been re­warded by com­mer­cial suc­cess? We used to dream of rid­ing jet-bikes across a clear blue sky – but in­stead we bought BSA Ban­tams and re­main firmly earth­bound.

Pho­tos by Kay Eldridge of Fo­cusedI­, RC RChive and Bon­hams auc­tion­eers

Right: Be­wil­dered po­ten­tial cus­tomers try to con­vince them­selves that it’s a mo­tor­cy­cle Left: Maybe this was a more efffffff­fec­tive ad camp­paign? It’s all ul­tra-mod­ern rocket ship stuff, right? Cut­ting edge, and things like that?

Above: Tucked away be­neath the fu­tur­is­tic pan­elling lives a re­mark­ably con­ven­tional en­gine Right: If you think it looks amaz­ing in red, just imag­ine how the Chimera must have ap­peared in its gold liv­ery. The other op­tions were a glossy green and...

Right: Made in metal. One elec­tric horn used as a styling de­vice Left: This truly is one en­tirely reemark­able mo­tor­cyc cle. Ev­ery­thing about it is s in­tended to grab th he eye, to be as diffe er­ent as pos­si­ble ffrom its con­tempo oraries Viewed in...

Right: Owner Basil of Head­works ma­chine shop in Mel­bourne was so keen to buy the Chimera that he paidd ‘way too much’ for it. Maybe we all know that feel­ing! Be­low: All-en­closed, swoop­ing body­work an nd weird front mud­guards. They’ll never catch on

Above: Some se­ri­ously ad­vanced think­ing went into the Chimera – it was a lot more than a con­ven­tional mo­tor­cy­cle in a smart frock. Ob­serve the ac­tual en­gine cases as part of the over­all styling job here Left: What’s in a name? The in­ter­net abounds...

Left: Ev­ery­thing swoops, some­how, even the seat and knee grips Right: The pilot’s view was suit­ably smoothed and un­clut­tered. Ob­serve with won­der those great grips! Throw away the body­work, fit a pair of con­ven­tional rear shocks, give it clip-ons and...

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