The black bike is pure American badass, styled like a prizefighter and with the same pugnacious manners. The platinum-colored bike is an exotic Italian beauty, long and lean with an undeniable air of exclusivity. Though the Buell 1125R and Aprilia RSV1000R appear very different on the surface, these stepbrothers from different moto-mothers both carry Rotax-made V-twins under their fairings. Do similar mechanical hearts make them more alike, or more distinct? We paired them off on the street and track to find out.
Although Aprilia is at the end of its 10-year agreement with Rotax and is currently developing its own V4 superbike in-house, the World Superbike-winning RSV1000R is still the firm's sporting flagship, and makes an excellent benchmark against which to judge the all-new Buell. The RSV is outpaced by modern sport-twins, such as the awesome Ducati 1098, but that's not surprising given that it's been largely unchanged since its 1998 release.
Not only does the 1125R carry Rotax's latest Helicon V-twin-the Austrian firm's second attempt at a superbike powerplant-but also a host of Buell-exclusive engineering innovations, including a fuel-bearing frame, split radiators and inside-out front brake. Our first ride on a pre-production 1125R at Laguna Seca last fall was inconclusive; comparing a production version against a proven performer is a great way to assess its real-world abilities.
 Twin dirtbike-style, side-mounted...  Twin dirtbike-style, side-mounted radiators cool the Buell. Unlike pre-production models, this one never overheated. |  A massive upper fairing contributes...  A massive upper fairing contributes to Buell's aptly named Quiet Zone cockpit. |  The 1125R's single inside-out...  The 1125R's single inside-out front brake looks trick, but lacks stopping power. |
Shared mechanical DNA aside, these two bikes couldn't be more different. The Aprilia represents conventional sportbike design theory, with typical chassis geometry, ergonomics and ride characteristics. The Buell, on the other hand, lives up to the company's old "Different in Every Sense" motto, with atypical geometry, unique ergos and distinctive handling characteristics.
Start in the saddle: Buell's Comfort Zone cockpit is one of the best in the business. The seat is broad, supportive and perfectly contoured, the bars are high and comfortably set, and there's plenty of legroom-the elusive all-day sportbike riding position. The Aprilia is a traditional Italian rack with a flat, firm saddle, long reach to low, narrow bars and high footpegs that will cramp anyone over 6 feet.
Straddling the RSV illustrates how much more compact sportbikes have become in the past decade. It feels massive, with a tall, wide tank that pries your legs apart and accentuates the bike's top-heaviness, especially at slow speeds. The Buell feels tiny by comparison. With its fuel carried lower and farther forward in the frame, the airbox cover between your legs is narrower and the footpegs are a few inches closer together. Combined with a bulbous fairing that moves air more like a Gold Wing than a GSX-R, the Buell offers undeniable comfort.
 The RSV's look was last updated...  The RSV's look was last updated in 2004, when it got dual headlights and a central ram-air duct. |  If the Aprilia's cockpit appears...  If the Aprilia's cockpit appears fairly modern for a 10-year-old bike, that's because it was updated along the way. |  With an Ohlins fork and Brembo...  With an Ohlins fork and Brembo radial-mount brakes, the Aprilia's front end is first-class. |
Despite being separated by 10 years of development and 12 degrees of cylinder angle (the Aprilia's cylinders are set at 60 degrees, the Buell's 72), there's no doubt both V-twins come from the same source. The two bikes sound nearly the same, with deep, growling exhaust notes and a surprising amount of mechanical clatter. Both also transmit a fair amount of vibration, especially at higher revs, despite aggressive counterbalancing measures (twin balance shafts for the 'Priller, three for the Buell). Vibration is especially noticeable through the Buell's footpegs, which mount directly to the engine cases.
Both bikes feel a tad thrashy at idle, but this impression disappears at speed. Except for a slight stumble off closed throttle, the Aprilia injects perfectly and offers smooth, linear acceleration from any rev point. Buell's DDFI 3 system is hugely improved compared with the pre-production units we tested at Laguna, but still not flawless. Gone is the off-idle abruptness, but the system still tends to hunt at constant throttle in the lower rev range and occasionally stumbles when you whack it open below 4000 rpm, causing the bike to lurch and shudder. A shame, this latter point, because the constant-tension drive belt and compensated countershaft sprocket combo otherwise provide lash-free forward motion.
Tim Carrithers, Dog-Eared Boy | Off The Record
I'd pick a winner here if we had one, but this conflict is a choice between bad and worse, a.k.a. the Aprilia. I loved the look. Very orange, very Italian and plenty of attitude. Then I rode it. Ergonomics by de Sade, an underwhelmingly asthmatic engine and limp suspension. I could muster up the time and money to deal with all that if we were talking about a well-preserved '98 Mille on eBay, but for a brand new $14,000 '08? There are too many other options out there.
Getting along with the Buell might be remotely possible if it didn't come with intractable fuel injection, a sticky gearbox, inconsistent brakes and only slightly less engine heat than a hibachi full of dry mesquite. But it does, so I can't.
AGE: 9.25 dog years HEIGHT: 6'3" WEIGHT: 15.35 stone INSEAM: 35 in.