Have you ever envisioned riding a top AMA Motocross team’s pumped-up and highly-tuned race bike on road rubber? Well now you can. And legally in all 50 U.S. states! Say hello to the Aprilia SXV 5.5. The $9499 SXV 5.5 is the Italian motorcycle manufacturer’s top-shelf Supermoto racer cloaked in full street-legal attire and seemingly designed to break every single traffic law in existence. Don’t say we didn’t warn you…
Lift the bike off its odd-functioning, but aesthetically pleasing spring-loaded kickstand and its remarkable how light the machine feels. Much less, in fact, than its already low fully-fueled, ready-to-ride 313-lb curb weight leads you to believe.
Straddle its ultra-tall 36.1-inch seat and one notices just how similar the cockpit feels to the aforementioned moto bikes, only just a hair wider. Similarities to the dirt world continue with a seat that is long and narrow and offers virtually zero support, making it painful to sit atop for even one fuel tank’s worth of gas.
Reach out to the Magura-sourced aluminum handlebar and your body is plied in an upright and commanding position, similar to what a rider would prefer if they were going to blitz around a Supercross track. The cleated metal footpegs provide a large platform to work from and are mounted low on the frame, equating to a relaxed foot position. The footpeg-to-seat-to-handlebar geometry is well proportioned, allowing you to comfortably ride the bike while standing when the seat eventually wears your rear end out.
Instrumentation consists of a compact and rectangular LCD display. The various functions of the gauge, including the clock, trip meter, and rpm readout can be cycled through via the small black button on the dash or a red “scroll” button. There’s also a red shift light, but it’s so small it’s hard to notice while riding. Notably absent is a coolant temperature readout, which is surprising given the high state of tune of the engine. There is, however, an assortment of engine warning lights.
Flip the key, thumb the starter button and the engine coughs and sputters to life in the same manner as a car that’s sat in the garage for too long. A fast idle knob is tucked away on the right side of the bike and its use is mandatory when the engine is cold.
(Top) The SXV is at home on the tightest, most winding road you can find. (Middle) A hybrid frame constructed from both steel and aluminum holds the V-Twin engine as a stressed chassis member. (Bottom) The 2-into-1-into-2 exhaust terminates into these lovely sculpted exhaust tips. The roar emitted from the exhaust at full-song is LOUD.
The scream emitted during fast idle from the engine’s internal mechanical flurry and the roar of the sleek and expensive looking 2-into-1-into-2 pipe configuration is wake-the-neighbors loud. But, once the engine is up to temperature, the fast-idle knob can be switched off and the engine settles at 2000 rpm, a far less attention grabbing volume.
Punch the throttle and feel the immediate burst of power from the unique 549cc liquid-cooled V-Twin engine. Designed and manufactured in-house by Aprilia, the motor features aluminum cases and a narrow 77-degree cylinder angle that’s said to reduce vibration and eliminate the need to use a counter-balance mechanism. Each piston gobbles up 80 x 55mm dimensions and squeezes fuel to the tune of a 12.1:1 ratio. The top-end consists of twin cylinder heads, each powered by a single chain-driven camshaft actuating four titanium valves.
A dry-sump system engine lubrication system reduces the size of the engine and there’s also separate engine oil and transmission/clutch reservoirs, ala Honda’s CRF250R and CRF450R motocross bikes. This reduces fluid contamination, extending oil life and maintenance intervals.
Right off the bottom, the engine pumps out upwards of 80% of its max torque from as low as 5000 rpm. Torque gradually increases, eventually peaking at 34.8 lb-ft at 9000 revs. This gives the engine such a wide spread of propulsion through its 11,400 rpm range that it makes it difficult not to loft the front wheel through each of the transmission’s five gears.
Despite employing an electronic fuel-injection system, the SXV guzzles down fuel through its twin 40mm throttle bodies like a 5000-lb SUV. In fact, the modest capacity of its 2.1-gallon fuel tank equates to a range of less than 80 miles depending how zealous you get with the right hand. Overall throttle response is excellent and provides a direct feel to what’s happening at the business end of the rear Dunlop tire around the racetrack at speed.
With the throttle pinned, the engine gains revs instantly and feels surprisingly similar to a hopped up and race-fuel fed 450cc Single. The free revving nature of the engine, extremely close transmission gear ratios, and ultra-short final drive gearing contribute to an engine that spins-up faster than any other road-going motorcycle on the market.
The SXV provides a direct connection between the throttle and the rear tire making it easier to explore the adhesion limits of the Dunlop rear tire.
This allows the SXV to offer mind-boggling acceleration performance from stoplight to stoplight. The sound emitting from the tiny sculpted metal exhaust tips only adds to the thrill. However, at freeway speeds you pay the price for its short gearing with the engine revving at upwards of 7000 revs and vibrating with such intensity that you actually think that the engine is going to explode. Accelerating further to its 105 mph top speed only exacerbates that feeling.
But outright speed isn’t what this bike is designed for. Point the nose into a turn and the SXV complies with virtually zero effort. The combined effect of its petite size, lack of mass and reduced gyroscopic-force of its engine allows it to be tossed around like few other production road bikes.
At a glance the bike’s frame appears to be aluminum, but in fact it is a hybrid design that uses a tubular steel trellis cage mated to pressed-aluminum side members. Aprilia claims this arrangement contributes to overall chassis rigidity. In typical Aprilia fashion, a long, brilliant-looking polished aluminum swingarm hangs off the rear of the bike.
Suspension is comprised of a 48mm Marzocchi inverted fork and a Sachs hydraulic shock absorber that operates through a progressive-rate linkage. The front suspension offers double adjustability in the form of compression and rebound damping, while the shock offers adjustable spring preload, separate high/low-speed compression and rebound damping. The bike offers a copious amount of travel at both ends, which makes quick work of speed bumps and curbs.
On the road the suspension reacts similarly to that of a modern off-road bike, offering considerably faster compression and return damping characteristics. Overall, the stock suspension settings are fine for even an elevated street pace, but lapping the racetrack exposed the shortcomings of the OE settings. Adding compression and rebound both fore and aft allowed the suspension to settle better when loaded and unloaded aggressively. Strangely, although the rear shock offers high-speed compression damping adjustability, you can’t access the adjustment due to the location of the muffler – not the best design. At lean the chassis is stable and offers plenty of ground clearance.
In terms of braking the SXV uses a German-made FTE radial-mount four-piston caliper that clamps onto a single 320mm wave-style rotor. The front braking apparatus is powered by a conventional non-radial master cylinder through a stainless-steel hydraulic brake line. The rear brake consists of a single 240mm wave-style disc pinched via a single-piston caliper through a metal brake line.
The front set-up offers a ridiculous amount of power, and combined with the feel at the end of the lever, it makes endos nearly mandatory at every stop. It was also fade-free during repeated hard motos around Grange Motor Circuit’s 14-turn 8/10-mile racetrack. The back brake functions equally well and along with the light and responsive action of the clutch helps band-aid the fact that the SXV is devoid of a slipper-style clutch during aggressive deceleration.
But buyers beware: Riding this bike is the quickest way for you to end up in the back of a cop car. Whether motoring down the road on the back wheel, getting sideways entering a corner, or drifting the rear tire through corner exit, the Aprilia SXV 5.5 is a true hooligan’s dream. Its chassis offers a tremendous level of both balance and feel, which gives the rider the confidence needed to flirt with the machine’s limits. Plus its soulful V-Twin engine is rambunctious, playful and pumps out so much power at all rpms it becomes the perfect toy for wheelieing, sliding, and any other wild drivers-license-jeopardizing antics. If you’re looking to experience the ultimate street-legal Supermoto than look no further than Aprilia’s SXV 5.5.