Raging · Buells!
Raging · Buells!
On track with the big-bore XBs
WITH THE NUTS AND bolts of the new Buell XB12 series untorqued and explained in this issue's tech preview, I drew the choice assignment of assessing on-track performance at the press launch. Is this a great job or what?
Buell served up a day of play at Road America, a scenic and
challenging circuit carved out of the wooded rolling hills of Elkhart Lake, Wisconsin. Four miles in length, RA is the longest and one of the fastest tracks on the AMA Superbike calendar. Our hosts had chosen to short-circuit the course, however, bypassing a pair of long, fast straights.
Once I got up to speed aboard the clip-on equipped XB12R Firebolt, the logic in their decision became quite apparent. The run through Kettle Bottoms, a gently bending flat-out section between the Carousel and Canada Comers, saw the Firebolt bumping its rev-limiter in top gear several hundred yards shy of the braking zone. The XB12’s taller primary ratio is effectively offset by the big motor’s reduced redline, resulting in a rev-limited topspeed approaching 140 mph on the dial.
Building a ton of torque down low, the engine maintains strong and seamless delivery right to its rev ceiling. I found myself frequently spinning into the soft limiter-detailed in Steve Anderson’s piece-in the early going. I soon resolved to short-shifting at 6200 rpm, which not only produced uninterrupted drives off comers, but cleaner upshifts, as well. Tapping into the abundance of midrange torque is where this engine’s flexibility is realized, allowing me to quickly gain confidence in the solid-handling chassis and predictable grip of the Dunlop Sportmax radiais.
Buzz in the pits between sessions related to tales of stubborn gearbox action and missed shifts. I, too, found upchanges to be a bit jarring, with the bike lurching ahead on clutchless shifts under full power. Smoother and fully reliable shifts could be achieved with use of the clutch, but the hand lever’s heavy action-the plates are more stiffly sprung than the XB9’s-and long reach was taking a toll on the tendons in my left arm. Maybe a hydraulic clutch for ’05, Erik?
High-effort input carries over to the right bar, too, with a very firm squeeze on the lever
squeeze on required to get the most from the single front disc. While lightly sprung, the throttle takes a bit more twist to pin open than I prefer. It all adds up to attention being wasted on basic control operation rather than a fully efficient attack of the course.
Buell has learned much about maximizing the chassis setup of its machines since the XB9R was first introduced at the Las Vegas roadcourse two years ago. This time out, suspension adjustments had been tailored to each individual rider’s weight and ability, resulting in lighter handling response than I’ve previously experienced aboard the Firebolt. Superb stability remains a standout characteristic of this short-wheelbased machine. A feeling of confidence and control exists even when it’s pushed beyond the traction limits.
Following four sessions at speed on the Firebolt, we moved over to the Briggs & Stratton Motorplex for a go on the XB12S Lightning. The .75-mile kart track proved an apt playground to toss the high-bar streetfighter model about. While the bike remained in second gear throughout the majority of a lap, kicks were had with wicked crossedup wheelies exiting a low-gear hairpin and hooliganesque hackers in a couple of braking zones. I definitely prefer the Lightning’s more upright riding position as an everyday mount.
With the XB12, Buell has closed the gap on current 600cc supersports. To get the most out of either type, you must always be aware of the rev range. On a 600 Multi, the trick is to stay above its soft midrange, whereas the opposite holds true for the Buell. Shift early and live large! Don Canet
