125cc Motorcycle: The Rumi Sport 125

In an era of post-war scarcity, a 125cc motorcycle with a 2-stroke engine could be a desirable machine. Especially one with attractive design features like the Rumi Sport 125.

125cc Motorcycle - rider cruising on Rumi Sport

With its distinctive "WAP-wap-thrap-WAP-wap-thrap" sound, the 1952 Rumi Sport was a 125cc motorcycle that made an impression.

Photo by James Adam Bolton

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1952 Rumi Sport 125
Years produced:
1950-1952
Claimed power: 10hp @ 7,400rpm
Top speed: 65mph (est.)
Engine type: 124.68cc air-cooled 2-stroke parallel twin
Top speed: 65mph (est.)
Weight (dry): 202lb (92kg)
Price then: $375 (est.)
Price now: $8,500-$14,000
MPG: 45-65 (est.)

If someone told you they were introducing a 10hp, 125cc motorcycle with a 2-stroke twin-cylinder machine like the 1952 Rumi Sport 125, would you be even remotely impressed? Probably not. These days, we’re spoiled by speed, power and efficiency. But 50 years ago, it was a different world.

Today, we can choose from an unbelievable assortment of motorcycles made to do anything we want. Up the road or around the world, it’s all so easily available to us. So try to imagine how it must have been back in the late Forties and early Fifties in an Italy still devastated by war. There were few decent roads, little infrastructure, not a lot to eat and not much to be had in the way of pleasure. Shoots of optimism were appearing though, and Italians were getting around again on two wheels. Following the lead of Piaggio with the Vespa and Moto Guzzi with its “Guzzino” 65, most of the major manufacturers like Ducati, MV and Mondial had a small-bore bike on offer; but frankly, these basic commuter machines were staid, slow and no fun.

And then there was Rumi. Like a bright torch in the gloom of post-war Italian motorcycle manufacture, the Bergamo-based factory led the way for others with daring and innovative designs, giving Italian teenagers something to aspire to by offering what was, for the period, an extraordinary looking motorcycle — the Rumi Sport 125.

High Art

When Donnino Rumi joined his father in the family bronze foundry business, Fonderie Officine Rumi, he decided Rumi had to diversify. Donnino was a shy but extravagant artist, with a visual bent not unlike that of Salvador Dali. He painted, sculpted, drew and designed, and joined his father in business after an education at the prestigious Carrara art academy in his hometown of Bergamo. Combine high art and metal making with a strong cultural desire for something bright and new, and it’s no wonder the products coming from the Rumi factory were so aesthetically original, technically well-designed and — most importantly — so appealing to the senses and emotions.

The Rumi Sport 125 was introduced in 1950, following the 125 Turismo, Rumi’s first production model. Unique in design and good looking, they went well, too, and both were instant sales successes. The 125 Sport engine boasted higher compression than the Turismo, and had slightly wider fins on the cylinder head to aid cooling. The 125 engine split horizontally (for quick and easy access), with a tiny one-piece crankshaft supporting double connecting rods and pistons with unusually shaped deflector heads. These were technical ideas that, while different, worked successfully in the Rumi engine. The Turismo engine was designed by Pietro Vassena, and then revised in 1951 by Giuseppe Salmaggi, who also designed the iconic Gilera Saturno. Salmaggi introduced the 4-speed gearbox for the Sport and twin-carbureted Super Sport by 1953.

Baffo’s Rumi Sport 125

My friend Fillipo d’Annibale, or “Baffo” for short (baffo is Italian for mustache), was one of those youngsters mesmerized by the Rumi Sport 125 way back when. “Nothing else makes a sound like a Rumi,” Baffo explains. “The noise from the exhausts is just special, and I remember hearing them pass by when I was a kid.” These days, after a long career in construction, he spends his spare cash and time finding and restoring the motorcycles he couldn’t afford as a lad, hence the Rumi Sport 125 now sitting in his shed, nestled amongst beautiful Parillas, Mondials and MV Agustas. “I have looked for a Rumi Sport for years,” says Baffo, “and as they’re rare nowadays, it took a lot of patience. Then I heard of someone selling a 1952 model not far from me. It had been restored well about 10 years ago, so I couldn’t resist, as there was no work to be done on it.”

The Rumi Sport is an unusual machine however you look at it. In an era when most small motorcycles had 4-stroke, single-cylinder engines, the Rumi has a 2-stroke parallel-twin engine sitting horizontally in the frame. The single Dell’Orto MB22A carburetor is attached to a sculpted two-branch manifold that carves a vertical arch before attaching to the cylinders. Polished aluminum crankcases incorporate strengthening yet aesthetically pleasing webbing, and the left-hand, one-piece casing also incorporates the chain guard, an unusual but beautiful approach, all cast in-house at the Rumi foundry.

The kickstarter is mounted high on the right-hand case, and has to be kicked forward, not back. It’s strange at first, and hard to kick while straddling the bike. The choke lever is mounted on top of the Dell’Orto, and once it’s set the Rumi starts first time from cold. Once fired a unique WAP-wap-thrap-WAP-thrap-wap emanates from the long chromed silencers, and of silencing they do little: the sound is deep and insistent, with none of the tinny ring-ding and like no other 2-stroke you will ever hear. It’s no wonder that the Rumi’s voice got under people’s skin.

What also makes this Rumi Sport 125 so different is the complete lack of toolboxes, side panels or other extra pieces of steel. The ignition works directly off the Dansi flywheel magneto, so there’s no battery, and the engine hangs off the open cradle, leaving only fresh air to be seen through the triangular frame. The only concession to any real clothing is the nacelle that covers the headlamp, incorporating the horn and supporting the speedo, and the valanced rear fender. The rounded and compact 3.7-gallon gas tank has depressions for the rider’s knees.

The seat is simply startling, and must be the single most bizarre-looking element of this motorcycle. Seemingly hanging off the back of the tank in mid air with no visible means of support, the bright red leather and chrome-studded saddle could have come off a child’s show pony. It flows neatly, connected by a flap to the tiny pillion pad, and complemented at the joint with the fuel tank by a padded parapalle; in Italian, it means a catcher or a wall to keep balls from going outside a playing area — enough said.

Looking under the gas tank, I can see the seat is firmly attached to a cantilevered and adjustable spring, a little like a monoshock suspension system. The only tiny concession to storage is found under the seat, where there is a little compartment with room for a spare spark plug and perhaps a small salami. A large friction damper dominates the rider’s view of the front end of the Rumi Sport 125, with the Rumi logo featured on the small, 120kmh speedometer.

Though the “cockpit” area is nicely thought out, with the top of the forks dressed with chrome caps, cool domed nuts and neatly routed cables, the bars are almost dead straight across and the non-adjustable levers have a span that can only be described as ridiculous. Strange, seeing as the rest of the Sport is obviously so well considered and the attention to detail is so remarkable.

On the Road

Riding the Rumi Sport 125 is just as remarkable, and it sounds like it looks — very different and hard to describe, but it could almost be mistaken for a loud 4-stroke twin. There’s none of that high-pitched 2-stroke buzziness, just a persistent drone that gets louder as speed increases.

The Sport does compare to a normal 2-stroke in that it has to be revved hard, giving good handfuls of gas to get the best from it. Taking into account the fact this is a 57-year-old motorcycle with 57-year-old technology, the Rumi flies for a 125, especially with a 180-pound tester on it rather than the intended trim Italian. First gear is tall, and I use the beautifully designed and cranked heel-and-toe gear lever to get up into third as fast as I can, and then accelerate hard. Response from the engine is precise and smooth.

The Rumi Sport handles very well on its skinny forks and plunger rear end. It corners admirably and the drum brakes front and rear are adequate for the performance offered, but just. Helping out is engine braking, which is considerable for a 2-stroke. I’m comfy on the sprung saddle, which soaks up bumps well, and while the levers and handlebars are annoying mainly because it wouldn’t have taken much to improve them, they don’t detract from the overall riding experience.

The speedo is typically Italian; inaccurate and a bit pointless. On a couple of straights, in fourth gear and attempting a crouch (not easy on something so small), I must have reached a good 50mph or 55mph, fast for an old and highly-strung machine. As they say, it’s not how fast you go but how you go fast, and on a machine that offers as much charisma, period charm and exclusivity as the Rumi, as well as great aural pleasure, that certainly counts for everything.

MC