I remember a time when 2 strokes were ubiquitous on the road. Their light weight, knife edge power bands, a power to H.P. ratio that wouldn’t look out of place on the specifications sheet of a 750 c.c. bike.
The minimalist chassis, coupled with a sub-150 k.g. weight, meant that 2 strokes were suited for kamikaze corner bashing, and head down antics in pursuit of top speed. But their rather anti social tendency to smoke unburnt 2-T lead to their swift banning in many countries around the world because of pollution concerns.
2 strokes are still with us, of course, in dirt biking, and in the GP 125 and 250 classes. Aprilia Malaysia recently launched the RS125 in this country at Sepang International Circuit. We had a go at it, so read our report after the jump.
The RS 125 is, as the name suggests, a 125 c.c. 2 stroke racing styled machine. Very closely patterned after their 2008 125 GP bikes, the RS125 is very much intended for the young racer, or racer wanna-be. A Rotax single cylinder liquid cooled engine with crankcase reed valve and a balance shaft delivers the power smoothly, although the engine needs to be brought up to the upper reaches of the power band before things start happening. Fuelling is via Dell’Orto carburetor, with the exhaust swept up the left side and tucked up out of harm’s way.
The cockpit is minimalist, as is to be expected from a racer, but it comes with everything you need to know, including a lap timer.
The twin beam aluminium frame brings everything together, with 40 mm USD forks, and there’s a hydraulic shock handling absorption duties at the rear. Brakes are typically racer like in feel and bite, with a single disc front and rear. The front brake is a 4 piston caliper, biting a 320 mm disc. More than adequate to bring the entire package of rider and bike to a stop in less time than it takes for you to read this sentence. The brakes are very controllable, and showed some signs of fading after several hard laps around the track. I suspect this might be because the rider is, perhaps, slightly heavier than the whippet weight 125 jockeys this bike was designed for.
The office, as you can well imagine, is a trifle cramped. This bike is definitely designed for slim, fearless, young men in their late teens or early 20s, not older riders who prefer to, shall we say, stretch things out a little. Saying that, once you fold your legs up onto the pegs, bend your elbows slightly outboard of your knees, ( and your elbows will touch your knees in race position), and place your chin on the tank, it feels right, allowing you to dream of being Simone Corsi.
But, the way to ride a small capacity 2 stroke can be summed up in two words. Corner speed. In this, the RS125 does admirably well. Although taking off calls for some cold hearted treatment of the throttle and clutch, once things get going, the 6 speed gearbox is smooth, each gear clicking into place without hesitation. You rev the engine towards 10,000 r.p.m., aim for the corner, and then, You. Must. Lean.
The RS125 is capable of some very extreme lean angles, allowing you to carry and hold the corner speed. At this stage, you really don’t want to start messing with the throttle, because any loss of engine speed takes a long time to claw back, due to the lack of torque. But if you do it right, the bike takes care of it all, allowing you to concentrate on the line, and the exit. Taking turn 9 at Sepang, the corner that is perhaps the hardest to get right, due to its off camber entry and invisible exit, was carved admirably well on the RS125. The light weight of the bike allowed this slightly ham fisted rider to choose a line, and lean over without fear of launching himself, and the bike, into the sky. This is something I couldn’t ever get away with on, say, a Ducati 999.
The RS125 is a motorcycle that rewards a brave rider. It is perhaps not suited for the rider who prefers something that requires minimal maintenance, or a daily commuter, as the Rotax engine requires regular maintenance to have performing at optimum. The handling is razor sharp, and easy to control, as any well designed motorcycle should be.
The peaky engine, together with its insane lean angle and corner speeds, makes this bike one for the racetrack, in the hands of a young racer.
