2008 Aprilia RXV 450

 

 

Hearing about it and seeing it are two different things. The Aprilia RXV450 sounds like little more than a technological sideshow on paper; it’s a fuel-injected, V-twin dirt bike with a frame and swingarm that look like they came right off a road-race bike. It’s interesting, but hardly seems like a realistic dirt bike. At best, you hope it’s a good for dirt roads, like a KTM Super Enduro or a BMW HP-2. But if you actually see it, touch it and sit on it, everything changes. It’s no larger than a modern motocross bike. It weighs no more than a Honda XR650R. And it hides that second cylinder so effectively you might not even notice that it’s there. This is a bike that changes the game. All the reasons that we assumed that a twin wouldn’t work off-road are now null and void.

 

 

TECHNOLOGY ON PARADE

Frankly, we don’t know much about Aprilia. We’ve heard that the company is one of the biggest motorcycle manufacturers in Europe, but we’ve only seen high-end sport bikes in the U.S. The company is owned by the Piaggio group, which also holds the keys to Vespa and Moto Guzzi. The RXV is its first attempt at a dirt-only bike for America. That seems strange considering it has blinkers and a license-plate bracket. In Europe, it’s certainly okay for the street, but things don’t happen quickly or cheaply over here. We would guess that EPA and DOT certification will come for the bike in the future, but Piaggio isn’t really saying that. At this point, the machine is considered a competition-only bike by the powers that be, and the VIN number reflects that. With its fuel-injection system the motor is clean enough, but the bike still doesn’t have such American peculiarities as a charcoal filter attached to the vent hose.

 

Aprilia has a computer-controlled management system that controls the spark and the fuel mixture. It’s the same system that has been in use on the street side of the company for years. The two throttle bodies point straight down from the airbox under the tank. With two cylinders taking up the space of one, things get pretty crowded down there. The heads are very compact. They have single overhead cams driving four valves per cylinder, and the exhaust system is a serpentine affair that exits the front of the forward cylinder and the back of the rear cylinder. Both head pipes join together in a large canister that sits where the airbox would be on a conventional dirt bike. There are two outlets at the rear of the bike, just under the rear fender. It looks pretty wild.

The frame is just as unconventional. It’s a composite of round steel tubes around the head pipe bonded to cast aluminum sections around the swingarm pivot. Then there’s the swingarm, which is like nothing in the dirt. Each aluminum arm is triangular in shape, sort of like what you might see on a MotoGP bike. It’s all certainly light, considering the machine’s dry weight of 278 pounds. That’s a good 15 pounds lighter than a Suzuki DRZ400S, and over 100 pounds lighter than any other modern Twin. Frankly, we didn’t think it was possible. Just imagine how much lighter it could be without all the lights and stuff.

There are some aspects of the bike that are conventional. The fork is a Marzocchi Shiver and the shock is a Sachs. That’s the same combo we’ve seen on Husqvarna dirt bikes. The brakes are Brembo and the tires are Michelin-although the rear is an FIM short-knob. We replaced it with a Dunlop 752 before we went very far from the truck.

 

IS IT A DIRT BIKE?

Absolutely. We took the RXV on fire roads, then we took it on trails, and finally we hit a couple of motocross tracks. We would never have done that on any previous twin-cylinder bike; not even the KTM or BMW-except perhaps as an experiment in abuse. The Aprilia feels like it should be in the dirt. Which presents the biggest problem. We don’t know what to compare it to. There’s nothing else like it, not even close.

If the standard is dirt-faring Twins, it already wins. But the bike has so much more potential that we naturally want to compare it to the best dirt bikes in the world. It certainly has enough power. The Aprilia has a mid-range surge that has to be experienced. Down low, there’s not much going on. But when the power hits, holy Moses, the bike lights up and moves. And even though the exhaust is super quiet, the sound that does trickle out of the two pipes has a distinct NASCAR flavor.

 

The result of the big mid-range hit is a lot of excitement and a little terror. If you have good traction you’ll scoot forward like a rocket sled. If you don’t, you’ll spin. That makes the bike hard to handle in rocks and on sketchy surfaces. On the other hand, it’s a gas on big sweeping turns when you want to break the rear end loose. In order to be really effective on tight, snaky trails, though, the motor really needs to produce more torque. If you keep it below the powerband it’s lazy and lends itself to clutch abuse.

 

With the engine management system so totally computer-controlled, it might be simply a matter of pressing a button on a laptop to give the motor more low-end. But we’ don’t know how-we’re as new to this EFI thing as anyone. The first place we would look for a solution is the exhaust. The stocker has some issues that could be easily solved. One is that you naturally want to use that section of the bike as a grab handle. Ouch. Another is that the stock system surrounds the rear shock and preheats it.

 

That last problem seriously limits the RXV for hard riding. The rear suspension is already soft, and after a few whoops the damping gets even lighter. We haven’t had a fade problem with Sachs shocks in the past, so it might be the muffler location combined with the weight. But at trail riding speeds you’re not likely to have much of an issue. The soft suspension makes the bike comfortable on tight trails. You can take the Aprilia any place that you would take a Honda XR650R. And that means anywhere, as long as you’re not in full-race mode.

TRAIL STUFF

Once again, we don’t know what to use for a yardstick. We would venture a guess that Aprilia doesn’t have much dirt experience, because there are a number of issues that would be easy to fix. For example, the bike has a paper air filter element, and the airbox isn’t particularly well sealed from dirt. It also runs a little hot-our bike was fitted with an optional fan that would keep spinning after the bike came to a stop. We think every little issue could be solved easily. In fact, Aprilia’s dirt-bike learning curve must have gone into overdrive this year. Former World Enduro Champion Stefan Merriman was hired to race the bike, and he’s already gotten some impressive results. On this side of the world, we know of at least one Baja effort that’s in the works.

 

Does that mean the RXV is a work in progress? Of course it is-what bike isn’t? We can testify that the Aprilia already is an impressive machine and that it has a lot more potential. How far can it go? We can’t say, but we wouldn’t be at all surprised if the bike is soon considered a serious contender-no matter what yardstick you use.

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