Photography by Jeff Allen
Aprilia wants a chunk of the off-road market, and its latest dirt-oriented addition, the MXV 4.5 motocrosser—based on the V-Twin-powered RXV enduro—proves that the Italian company plans to remain unique in a market dominated by Singles.
Characteristics the MXV doesn’t share with the RXV are the enduro’s portly weight, bulbous tank shrouds and street-legal necessities. The MXV weighs 40 pounds less than the R (237 pounds without fuel, identical to Kawasaki’s KX450F), achieved in part by shedding the enduro’s battery and starter motor, meaning that the engine is kick-start only; it fired right on cue every time, so we didn’t miss the “magic button.”
The 449cc, 77-degree Twin features four titanium valves per cylinder actuated by single overhead cams, with electronic fuel-injection and two mapping options (hard/soft) selected via a handlebar-mounted switch. The engine features dry-sump lubrication using a crankcase-integrated reservoir, while the four-speed transmission has a separate oil supply for improved longevity.
A vibrant exhaust note from the twin titanium mufflers grabs attention, yet meets the FIM-mandated, 93-decibel sound regulation. Power is peaky, much like a two-stroke’s. Bottom-end grunt is lacking in either map setting. I used the “soft” map 90 percent of the time, which gave more control over the monster top-end rush.
The hybrid steel/aluminum-trellis frame feels very slim between the knees. The low, 1.9-gallon fuel tank and narrow radiator shrouds allowed me to easily slide up the narrow seat to get weight over the front end. Suspension comprises a hydroformed aluminum swingarm controlled by a fully adjustable (including high- and low-speed compression damping) Sachs shock with rising-rate linkage. A 50mm Marzocchi fork with compression and rebound adjustability resides up front. The fork felt good over small chop but easily blew through its travel on bigger bumps and jump landings, as did the shock.
The MXV has a unique feel that takes a while to get used to, with odd weight distribution that makes the bike feel heavier than it should. A wallowing sensation while hitting jump faces was disconcerting and sapped my confidence. Lowering the fork in the triple-clamp eliminated some, but not all of the handling issues.
Anyone looking for a unique motocrosser will find the $8499 MXV 4.5 appealing. It has a few quirks and requires effort to get the chassis set up properly, but the end result adds a lot of flavor to a class that has been all too vanilla.