Go Small or Go Home

After making a name for itself selling small to mid-size scooters, Italian firm Aprilia has been carving out quite a niche in the sport bike world.  Their initial attempts at full-on sport bikes were considered by some in the press to be cute attempts to join the big boys from Japan and Europe.  The roaring thunder emanating from the Rotax-built twin in the RSV 1000 silenced many of the critics and helped cement Aprilia as a legitimate power in the superbike wars.

But Aprilia's heart is still the small-bore segment.

And there is no more proof of this than their newest small bike, the RS4 125.  The familiar two-stroke is gone as this Aprilia is powered by a liquid-cooled four-stroke single displacing 125cc's and pumping out 16 horsepower.  It also sports a 41 mm inverted fork, four-piston front brakes and a stout aluminum frame.  Topping it off is styling reminiscent of the much larger RSV4 superbike.  The RS4 125 is aimed the teenage rider looking to get his or her feet wet in the sportbike pool. 

Let's go back and focus on something for a bit: 16 horsepower. 

Sixteen. 

Don't let that number fool you into thinking this bike is a few steps above a Power Wheels motorcycle.  This machine is full of serious engineering.


The engine features dry-sump lubrication to save weight and physical engine size.  Lessons learned in World Superbike and GP 125 found their way into the die-cast aluminum chassis, creating a stiff frame that's still light weight.  Clamping the 300 mm front disk is a radially-mounted four-piston caliper.  The exhaust is hung low in the chassis for better mass centralization.  Even the fairing was wind tunnel-tested for maximum aerodynamic efficiency.  The whole package has ready-to-ride wet weight of just 264 lbs. 

That's an amazing spec sheet for a small-bore bike.

Even though this machine is marketed toward 16-year-olds, its serious engineering can make any experienced rider take notice.  It's a bit like a road-legal (in Europe) GP 125 bike much the same way a Ducati Desmosedici is a road-legal MotoGP bike.  The stiff chassis, big brakes and willing engine all combine to get those enthusiast juices flowing. 

Now if it will only come to the U.S.

An almost dead-ringer for an RSV4, the RS4 125 has Italian good looks and charm in spades.

The LCD display mimics those found on larger sportbikes and adds a minimalist touch to the cockpit.  Make no mistake, this bike is all business.