Gilera CX125 - Beginning the Future

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Up until recently there was an interesting category of sporting 125cc two-strokes that dominated the European beginner bike market. Countries like Italy and Britain restricted new teenaged riders to 125cc machines as a “learner” category that was well catered to by most of the major manufacturers. These learner specials often had race-replica sport-bike styling and sharp dynamics to appeal to the masses of hormone-addled 17 year olds who wanted to look fast, even if their machine couldn’t have more than 15bhp by law. Four-stroke 125s were always available but the hot ticket up until recent years was always a rip snorting two-stroke that could be derestricted once you had completed your learning period. While the four-strokes and two-strokes made the same power when restricted, the smoker could be uncorked afterwards to unleash the full fury of the mighty single – as much as 35-odd horsepower, manic power in a machine that scarcely cracks 250lbs with a full tank of fuel.

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Most of these learner specials are by and large inspired by their bigger stablemates – thus you could get a miniaturized Yamaha YZF-R, Honda NSR/CBR, Aprilia RS, or even an 8/10ths replica of the iconic Ducati 916 sold as the Cagiva Mito. There was, however, one notable exception to this rule where a manufacturer went all in and gambled on producing a totally unique design that would break the mould. Gilera produced what was possibly the weirdest 125 sport bike of all time – the short lived and radically-styled Gilera CX125, which would quickly earn a status as a cult special that had some of the most futuristic design to ever grace a “beginner” bike.

Gilera is one of those unfortunate cases of a once-great marque that has recently fallen into obscurity and the realm of the mundane. Gilera was once a mighty force in motorcycle competition, producing some of the most advanced Grand Prix machines of the 1930s, 40s and 50s. Gilera today is a mere footnote in the history of Italian motorcycle brands and a feather in the cap of parent company Piaggio, who debased the once-storied name it by slapping its logo onto a series of dull scooters. It wasn’t always so.

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Giuseppe Gilera founded his namesake company in 1911, after having apprenticed with the firms Bianchi, Moto-Reve, and Bucher and Zeda as a mechanic. He had built his first complete motorcycle in 1909, a 317cc overhead valve single of his own design. Gilera began as a small racing team, but a fortuitous meeting with a wealthy motorcycle rider who was impressed with Giuseppe’s talents led to the creation of a proper manufacture. A factory was established in Arcore, which would remain the perennial home of Gilera until Piaggio shuttered the works in 1993.

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Gilera achieved some successes in racing with sidevalve and overhead valve singles and twins through the 1920s and early 30s, but it would be their four-cylinder racing machines that would establish the marque as a world-class manufacturer that could compete at the highest levels of racing. In 1936 the company was given the opportunity to purchase the 500cc Rondine (Swallow) four-cylinder competition engine, a design that would define the company's racing successes for the next twenty years. The Rondine four was an evolution of the single-cam Gianini Remor Bonmartini (GRB) air-cooled engine designed in 1923 by noted engineers Carlo Gianini and Piero Remor. It was the genesis of the modern four-cylinder layout; it had an across the frame transverse layout that distinguished it from earlier longitudinally mounted fours, initially introduced to aid air cooling but also having the benefit of allowing a much shorter and more nimble chassis. While today we take multi-cylinder machines for granted, in the 1920s and 30s all levels of racing were dominated by singles (and the odd twin), favoured for their simplicity, light weight, and compact dimensions. In fact four-stroke singles remained competitive in Grand Prix racing right up until the 1950s, when multis finally began to reach maturity and consistently win races.

The Rondine was an evolution of the GRB developed in the 1930s while under the ownership of aviation concern Compagnia Nazionale Aeronautica– it shared the basic architecture of the GRB but benefited from liquid cooling and supercharging to produce an impressive 60hp, with later revisions pushing 87hp. While fast, the CNA-Rondine suffered from reliability issues that hampered its success.

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Gilera purchased the Rondine racers from CNA and campaigned the machines during the interwar period with some racing successes and several world records. Supercharging was banned from competition in 1946 and Piero Remor, who was now working for Gilera, developed a new engine design in 1947-48. The 500 4-C air-cooled four would prove to be one of the most successful racing engine of the 1950s, and remained the machine to beat until Gilera retired from racing in 1957, winning the 500cc World Championship in ‘52, ‘53, ‘54, ‘55 and ‘57.

So how do we segway from four-cylinder, four-stroke Grand Prix winners to a weird and futuristic two-stroke single aimed at teenaged riders? This way:

After the company withdrew from competition in '57, Gilera changed direction abruptly. They downplayed their hitherto successful line of four-stroke singles and began to focus on motocross and off-road events in association with independent specialist Elmeca. Sales declined through the 1960s and by 1968 the company was in receivership. In 1969 Piaggio took over the ailing company and began to restructure the lineup. After the takeover Gilera made a range of small four-strokes and a few interesting prototypes, but they would not become truly successful until they returned to the production of motocross and big trailie machines in the early 1980s. At this point street machines were relegated to small two-strokes, as well as a limited revival of their storied Saturno name with a sport bike built around big four-stroke singles taken from their line of large trail bikes. Things looked bright for the marque in the late 1980s. The factory had been modernized and the products updated significantly by 1985, and Gilera had built a reputation for advanced engineering and for producing very competitive machines in a variety of categories.

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By the end of the 1980s Gilera had produced a range of successful and advanced liquid-cooled two-stroke 125s that were sold in both street (including the RV, MX, KZ and KK series) and off-road (R1 and RTX) guises. The 56x50.5mm liquid-cooled single shared among the various models was a clean-sheet design introduced in the 1984 in the RV125. The loop-scavenged engine featured reed valve induction and a six speed gearbox, much like you’d expect from any Japanese two-stroke of the era, but unlike the Asian competition the Gilera mill had a counter-rotating balance shaft, CDI electronic ignition, and an electric starter. Reviewers accustomed to the broken-blender vibration of typical two-strokes noted the smoothness of the engine compared to everything else on the market. And it didn’t sacrifice any muscle for that velvety power – initial versions made around 25 horsepower, later highly tuned SP variants had as much as 35 hp. To us modern riders habituated to four-strokes, that sort of power out of a street-legal 1/8th litre machine is unfathomable, and even the latest crop of 125s scarcely produce any more power than Gilera was extracting from their tiny singles in the late 80s.

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The KZ and KK were the first fully-faired 125 sportbikes to be produced by Gilera in the mid-80s, and garnered accolades from the press for great handling and impressive performance in the category. These machines would evolve into the advanced 1988 SP-01, which combined extremely modern styling and high-quality suspension components with a highly tuned 35hp engine. The mighty little 125 featured a sky-high 13.5:1 compression ratio, a 32mm Dell’Orto carburettor, and an exhaust valve (dubbed the Automatic Power Tuning System) to boost midrange performance. The frame was a massive (for a 125) twin-spar beam design that appeared to be aluminium at first glance, but was in fact steel. The whole package weighed approximately 250 lbs dry and was capable of a claimed top speed of 106 mph. The design was refined with the introduction of the SP-02 in 1990, which begat the Crono in 1991. Looking at the SP/Crono you’d easily mistake it for a mid-90s 250 or 400cc machine. The SP-02 and Crono even featured 40mm inverted Marzocchi forks, a luxury normally reserved for the most advanced superbikes of the era, and looked more like a high-tech, high-quality Japanese home-market mini-sportbike than a European learner bike.

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The CX design was heavily based on the SP/Crono architecture, with styling by noted Italian designer Luciano Marabese. Marabese was quite prolific during his tenure at Gilera – he also penned the KZ, KK, Dakota, MX, XR and SP models, and would go on to sketch the Moto Guzzi Centauro and Griso. The CX concept was unveiled at the 1989 Milan EICMA show enclosed in a plexiglass display. The prototype CX (supposedly named for its low drag coefficient) was like any other concept bike – impressive to look at, but scarcely believable as a potential production machine. Here was a tiny sport machine with fully enveloping bodywork that looked like something straight out of a Japanese cartoon, with a remarkable single sided suspension – on both ends. While single-sided rear swingarms had been around on production machines for a few years already (you can thank Honda for that innovation with their patented Pro-Arm), nobody had seen a single-sided front swingarm on anything except the ELF experimental racers. Indeed, the CX was clearly inspired by the ELF machines, particularly the 1984 ELF2 with it disc-shaped alloy wheels and all-enveloping bodywork.

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It was scarcely believable that the CX would be slated for series production. But it was true, and it would hit the market in 1991 as an honest-to-God working motorcycle that featured the same space-age styling and bonkers suspension that the 1989 prototype had introduced. Not only that, it was only slightly more expensive than the Crono 125 that it shared showroom space with. And with good reason – the CX was essentially just a Crono with a funny front end and some swoopy bodywork.

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The styling was outlandish and thoroughly modern, but not groundbreaking. Fully enclosed bodywork and highly streamlined designs were all the rage in the late 80s (see also Bimota DB1 and Tesi 1-D, Ducati Paso, and Honda Hurricane) though the CX took the theme a bit further by extending the beak of the front end over the front wheel for better aerodynamics. The 17-inch alloy wheels, manufactured by Grimeca along with the brakes, also fit this aerodynamic theme with a large lens-shaped central hub. The marketing material touted the CX as being so slippery that it was as fast as its more powerful (but unnamed) competitors. In reality the claimed top speed was down slightly compared to the Crono and SP at just a shade over 100 mph.

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Under the bodywork the production CX125 shared the same twin spar steel frame and engine as the Crono, with a slight revision to the exhaust system to boost midrange at the expense of some of the top end. Compression was reduced a half point to 13:1. Claimed power was now 30 hp versus the Crono’s 35, and the APTS valve was controlled electronically rather than mechanically.

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The front suspension, manufactured for Gilera by Paioli, appears highly advanced at a glance but is actually remarkably simple – and it offers no real advantages over traditional telescopic forks. In fact, it is a telescopic fork - singular. The best summary of the CX front suspension is that it is the front landing gear of an aircraft applied to a motorcycle. The wheel hub and brake is attached to a swinging arm that connects inline with a 45mm telescopic tube held centrally by the, um, “triples” mounted in the traditional location. Steering is direct, in that the handlebars move the triples, which rotate the front assembly, with a control arm keeping the whole shebang straight (without the linkage connecting the swingarm to the triples the telescopic tube would rotate freely, same as a traditional fork). No hub centre or forkless shenanigans here, it's all quite straightforward once you examine the details.

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Despite looking completely unique the design is actually remarkably conventional – and carries all the same characteristics as a regular front end. Unlike the other funny-front-ends discussed on OddBike previously, the CX offers no appreciable advantage when compared to a traditional telescopic design because it is a telescopic design. Suspension forces are still channelled through the same areas of the frame, and the action is very similar to a regular pair of forks, just merged into a single slider. You still have the age-old problems of stiction, flex, deflection, dive, squat, and geometry changes under compression. Engineering aside, it looks cool - and that was the whole point. The CX wasn’t a groundbreaking machine in anything but styling. It looked (and still looks) like nothing else on two wheels, but under the skin it is pretty straightforward. And easy to manufacture – keep in mind that the CX was intended to be an affordable 125, not an expensive flagship, and only cost a few percent more than the Crono with which is shared showroom space.
Such it was with much of the CX – it was all show, not much substance. The all-encompassing bodywork (with the requisite early-90s dayglo graphics) looked the business but hid the all the conventional bits underneath. The “Integrated Security System” proudly touted in bold script on the tail simply referred to having a locking seat and filler caps. Ignore the time-travelling style and marketing hype and you have a competitive, but not outrageous, 125 sport bike.

In the press the CX was well received. Handling erred on the side of stability balanced by the flickability offered by such a lightweight machine, with a stiff suspension action due to the limited travel of the front end. Praise was sung for the impressive powerband of the tiny engine, which combined adequate midrange with a shrieking top end rush once the exhaust valve opened between 8000 and 12000 rpm. While not torquey engines by any stretch, Gilera 125s were noted for being slightly more tractable than their competition. The reviews are underwhelming for those expecting some far-fetched oddball machine that behaves like nothing else. There is a certain strained quality to the prose that conveys the reviewer’s apparent disappointment with how ordinary the CX was on the road, like they are desperately trying to find a way to make it sound as cool as it looks. It’s not that the CX was completely underwhelming; it was a good bike, but it felt far more conventional than the styling suggested.

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While the CX garnered more than its fair share of attention due to its radical styling, it wasn’t particularly popular. Funky looks and nifty front end aside, it performed like the sister Crono model, but was slightly slower and cost more money. Bad formula for a sales success, particularly when you are trying to appeal to speed-craving teenage punks who are more likely to gravitate towards the sexy race-replica with the extra bragging points on the spec sheet rather than the avante-garde styling exercise. It probably didn’t help that popular opinion of the CX varied between “incredibly cool” and “tragically ugly”.

Thus production of the CX125 was discontinued after less than a year and only 1000 examples, about 500 of which were allocated to the Italian home market. Even then there was enough leftover stock for the CX to be sold “new” until 1993, when Piaggio pulled the plug on the Arcore factory, moving the operation to Pontedera and discontinuing Gilera’s motorcycle production. After 1993 Gilera was limited to producing scooters of various descriptions and displacements, which they continue to do today. They did return to racing, winning the 2001 125 GP and 2008 250 GP championships, but the production of street motorcycles was over. A few promising concepts were unveiled in the 2000s that suggested a possible comeback, but they all came to nought – the 2002 Supersport 600 turned out to be vapourware, while a proprietary 839cc V-twin design was poached by Aprilia. It seems Piaggio has developed a reputation for stifling interesting brands and cool models – just ask the Moto Guzzi die hards about all those new sport models they don’t have, or check out the latest (nonexistent) lineup of Laverdas. Sad though it might be, passion doesn’t pay the bills - scooter sales do.

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Today hot learner specials like the SP, Crono and CX125 are a dying breed. Increasingly strict emissions laws are putting the squeeze on remaining two-stroke designs, and most companies have abandoned smokers to focus on four-stroke designs, which are far cleaner and more reliable (at the expense of about, oh, 60% of the power). There are a few holdouts that have managed to make two-stroke 125s clean enough to meet Euro III specs (the Aprilia RS125 and Cagiva Mito SP525 being the most notable), but it seems that the future is in four-strokes, much like it was with larger displacement machines in the 1990s.

The Gilera CX125 was a major gamble from a company that was riding high on a string of successes that didn’t pay off in the showrooms - a bold move that is unlikely to ever be seen again, particularly in the accessible price point that the CX targeted. While aesthetically daring, the CX was remarkably straightforward under the skin and far less advanced than its space-age styling suggested. Success or not, the CX was an innovative product produced by an interesting motorcycle company that has since been castrated in the most humiliating way possible: having its once-proud name emblazoned on a series of scooters.

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Interesting Links
Launch review of the CX125
Real Classics comparison of the CX125 and Moto Morini Dart 350