2008 Buell 1125R | Motorcycle Review

Water-cooled Powerplant

When asked how long he has wanted to build a water-cooled production sportbike, it takes a moment for a telling expression to wash over Erik Buell’s face. A nearby engineer overhears the question and erupts with knowing laughter—yet another unspoken confirmation that a large part of Buell’s nearly quarter-century of bike building has been tinged with a bit of unconsummated technological craving.

Helmet: AGV TI-Tech Tattoo Red
Eyewear: Tag Heuer
Leathers: Spidi R-2 Kangaroo
Gloves: Spidi Race Vent
Boots: Gaerne G-RS. (Click image to enlarge)

On one hand, Buell’s unconventional motorcycles have boasted a visionary embrace of forward-thinking engineering through their so-called trilogy of tech: mass centralization, low unsprung weight, and chassis rigidity. On the other, the bikes’ air-cooled, pushrod Harley motors have been most charitably called "nostalgic," and most mercilessly referred to as "antiquated lumps." Because a track-ready superbike is only as good as its horsepower-churning heart, Buell finally took a quantum leap by utilizing its first water-cooled powerplant on the eve of the company’s 25th anniversary.

Parent company Harley-Davidson’s resources were stretched thin, so Austrian engine-builder Rotax was tapped to create a purpose-built mill for the new flagship. A water-cooled, liter-plus engine was specified for world-class performance, and Buell set out to frame it with a chassis that could cope with its considerable output. The resulting 1,125cc V-twin produces 146 hp (with an additional 5+ horses when ram-air is in effect), and its displacement was deemed significant enough to inspire the name of Buell’s new sportbike: 1125R. (Click images to enlarge)

The 1125R’s competition consists of slickly sculpted superbikes from around the world, but its appearance caters more to functionality than absolute aesthetics. Up front, a wide, squat fairing precedes two large radiator shrouds that curve inward, greedily scooping intake air for the V-twin. Moving rearward, the bike’s tall frame dominates its profile and lends the 1125R a resemblance to Buell’s past, tapering inward as it grazes the partially visible powerplant. The hump of the false gas tank forms an obligatory shape, while the task of bearing fuel is carried out by the aforementioned frame. In the name of mass centralization, an underslung exhaust adds a bit of verticality to the bike’s stance. A rather unremarkable rearend features a cowl which, when removed, hides a small, removable passenger seat.

Further conversation with Erik Buell reveals that his engineering background is infused with an appreciation for eye-pleasing shapes. Though eager to cite the benefits of a fairing that creates positive airflow and reduces turbulent Von Kármán vortices, he also expresses as much enthusiasm about the 1125R’s similarity to the female form. The bike is not quite a lusty, Italianate celebration of all things sensuous, but it does reveal that Buell’s industrialism can be peppered with discreet joie de vivre.

Wrap your legs around the 1125R, and its dimensions come across as a bit bulky, despite its slimming black hue. However, rock it from side to side or roll it backwards and forwards, and its lightness becomes apparent; this is, after all, a bike whose wet weight minus fuel is claimed to be one pound less than a Ducati 1098. Ergonomics are less unrelenting than the Duc, with a slightly more relaxed, upright posture. The gateway to motion is a pneumatically operated slipper clutch, which utilizes less moving parts than traditional designs and reduces lever effort by sourcing vacuum pressure from the engine’s intake manifolds. Releasing it from a standstill avails the V-twin’s insistent low-end torque, easing the bike forward without hesitation. (Click image to enlarge)

First gear is tall enough to warrant some clutch slippage to facilitate takeoff, but then the rider is a mere throttle twist away from a steady, predictable increase in power. The path from zero to redline traverses 10,500 rpm, and at roughly halfway to maximum revs, vibrations emerge at the handlebars. Those sensations intensify and spread to the footpegs as the tachometer approaches red, and while the shaking is not quite as dramatic as past Buells, the bike exhibits enough buzziness to jolt you awake like a heavily spiked, two-wheeled caffeine substitute. Power delivery is generally tractable and accompanied by a satisfyingly raucous exhaust note, and a slight surge of thrust at around 8,000 rpm rewards high rev addicts with an added kick of acceleration.Buell engineers refer to the feedback they sought to elicit from the gearbox with the onomatopoeic "snick snick," and the rider’s left foot is, indeed, treated to a low effort, positive-feeling shift lever. Clutch-free shifts are easy and addictive, but tap the lever too lightly and you might encounter a false neutral between high gears. The 1125R’s clutch action is easy. Aggressive downshifts are well mitigated by slipper clutch mechanism, which absorbs the difference in wheel speed and engine rpm without drawing attention to itself.

In the interest of reducing the 1125’s unsprung weight, a perimeter-mounted front brake system with 8-piston, 375mm rotors, and the same calipers as Buell’s XBRR race bike., are utilized. Though the system lacks the feel of radially mounted brakes, the 1125R is capable of tremendously powerful stops during laps at Mazda Raceway Laguna Seca. Conversely, exiting tight bends such as turn 11—which unfolds into the tantalizingly fast straightaway—reveals the breadth of the twin’s powerband, as it easily spools up and catapults the screaming bike down the straight.

The bike’s flickability is put to the test at Laguna’s famous corkscrew, and while it takes a bit of initial effort to lean the bike over, the 1125R remains stable and planted during cornering. The front end exhibits a touch of wiggle under hard acceleration and surface irregularities, but the shake is not dramatic enough to warrant a steering damper—an opinion, not surprisingly, that Erik Buell adamantly agrees with.

Photograph by Kevin Wing

On public roads, the 1125R feels all the more overqualified, and its comfortable ergonomics induce no feelings of strain or discomfort after a full day of aggressive riding. Our only complaints regarding the pre-production unit we tested consist of a few items Buell assures will be resolved before the bike makes it to market—jerky throttle response at low rpm, the heavy transfer of engine heat to the rider in warm weather, and the fine tuning of the front suspension.

And so the Buell 1125R makes itself equally apropos on the track or the road, cutting a distinctive silhouette as the sole superbike offered by an American manufacturer. It is certainly an unusual motorcycle, one that disregards the unwritten design rules whispered by virtually every other brand. And, like the Ford Model T, another groundbreaking product in American history, you can get the 1125R in any color you want—as long as it’s black.