Buell 1125R isn’t about thunder or lightning. Just speed

It was a 100-mile day of wide-open throttle, hard braking and high-speed corners. A day divvied up into 1.8-mile chunks as I sped around the Streets of Willow racetrack on the 2008 Buell 1125R again and again, faster and faster.

It’s to Buell’s credit that I wanted to twist the grip harder, lean the bike farther, brake deeper into a turn and downshift closer to its 10,500 rpm redline with each successive spin around the raceway. When it comes to track riding, the best bikes are the ones that don’t distract. Fluid and easy to operate, they create a sense of trust, then fade into the background, letting you do what needs to be done -- go faster.

By that measure, the 1125R more than meets the mark.

Buell Motorcycle Co. has long billed itself as the lone manufacturer of U.S. sport bikes, but that claim should come with an asterisk. In the 24 years Erik Buell has been building bikes, most of them have been geared for the street, not the track.

With its brand-new 1125R, Buell continues that tradition but nudges it in a more racerly direction, working with pedigreed track stars to fine-tune the superbike’s dynamics and skipping the cute elemental nicknames of previous models for one that’s to the point and alpha-numerical. There’s no thunder. No lightning. The 1125R is exactly what the name implies -- a red-blooded racer of a 1,125 cc sport bike that’s 100% twist ‘n’ shift fun.

For Buell, 1,125 is a brand-new displacement, and it comes courtesy of a brand-new engine. Designed in conjunction with BRP-Rotax, the Helicon V-twin doesn’t just have a superhero-like name; it acts the part, muscling in with a meaty 146 horsepower and 82 pound-feet of torque that are still entirely congenial.

That makes it the most powerful Buell engine -- an increase of 43% over the larger, 1,203 cc Thunderstorms on the Firebolt, Lightning and Ulysses -- and the one that generates the most heat. That’s why the 1125R is the first liquid-cooled engine in a street-legal Buell.

The Helicon engine is the most major advance for the 1125R, but there are others in the Buell “trilogy of tech.” Mass centralization, low unsprung weight and chassis rigidity are the name of the game for every Buell that rolls off the line. So, like most Buell bikes, the 1125R stores its fuel in the frame and slings its exhaust under the engine; the brake rotors are mounted directly to the rims, reducing torsional loads to zero; and the motor bears at least some of the burdens of the frame as a stressed member.

The 1125R just caffeinates the trilogy, producing more power more manageably in a lighter-weight package than any other production Buell bike. At 375 pounds dry, a power lifter could hoist the 1125R. It’s the second-lightest bike in Buell’s eight-model lineup; only the 492 cc Blast is lighter, and that’s by a mere 15 pounds. Fill up the 1125R’s 5.6-gallon, in-the-spars tank and its twin side-mount radiators, and still, you’ve barely tipped the 400-pound mark.

Like any sport bike that’s worth riding, that weight was centralized, lowered and balanced to the point of invisibility in motion. Handling-wise, responsiveness was increased by slimming the torque-y V-twin to a narrow 72 degrees, inching it forward in the chassis and rigidly mounting it in the frame.

On the power side, the down-draft throttle bodies were fattened up, the valve angles were steepened and a ram air system was added to increase intake and give the bike an extra boost at the slightest flick of the wrist. That power wasn’t just linear. It was smoothly transmitted all the way down the line, from throttle to valves and onward, to the close-ratio six-speed transmission and the automatically adjusting secondary belt drive.

If twisting the grip was a time warp, slowing down was practically worry-free, thanks to a hydraulic vacuum-assist slipper clutch that stopped my rear tire from skipping during high-speed, heading-into-hairpin downshifts and smooth front brakes that pressed a whopping eight pistons into duty on the caliper.

Suffice to say, riding the 1125R was, to steal a name from a fellow Buell, a blast.

susan.carpenter@latimes.com

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