Erik Buell had come a long way by the time Harley-Davidson axed his eponymous motorcycle company late in 2009. After 26 years trying, he had finally proven his American sportbikes were competitive with the best from Japan and Italy by winning the 2009 AMA Daytona Sportbike Championship. But way back before this racetrack success ... before the advent of the liquid-cooled, Rotax-built Helicon motor that powered the championship-winning 1125R ... back when company politics kept Harley's antiquated, air-cooled, pushrod V-twin tied like a boat anchor around his ankle ... Buell touted his machines as "the ultimate back road bikes."
This wasn't a cop-out, and Buell's agile, upright "sportfighter" motorcycle designs made the most of The Motor Company's technically crude but torque-rich powerplant-especially tuned to Buell's potent Thunderstorm specs. "Honestly, the air-cooled motor was perfect for the streetbike application," Buell reminded us recently. "It has loads of torque, and a lot of flywheel isn't a bad idea on rough, dirty roads. It's easier to put that power down. In fact, it's really fun!"
Buell/Harley reps had been urging us to do an XB-based project bike for some time, and even offered a scratch-and-demo 2008 XB12S Lightning as a starting point. We were waiting for inspiration to strike when financial realities hit the cooling fan in October '09, and Buell was shut down. That was all it took to snap this project into focus. We decided to construct a two-wheeled tribute to Erik Buell's original vision of the ultimate back road bike: light, torquey and insanely fun to ride.
Polished stainless-steel end cap is the only indication the muffler has been modified by D
Fully adjustable, remote-reservoir Öhlins shock was custom-built to our specifications by
The chain-drive conversion swingarm from the old Buell race kit is now available through E
The long-stroke, 1203cc Thunderstorm V-twin is already a sweet street motor in stock form. It delivers a robust 70 lb.-ft. of torque with that singular, heavy-flywheel character that feels like you've been whacked by God's own nine-iron whenever you crack the throttle. More is always better, however, so we delivered the bike to air-cooled Buell guru Danny Bilansky at Hal's Harley-Davidson in New Berlin, Wisconsin. Having twice won the ASRA Pro Thunderbike National Championship, he knows how to make XBs go.
Our supermoto-inspired Super TT is purposeful, not pretty. Motocross-style graphics from D
Bilansky began with a little low-buck hot-rodding, inserting off-the-shelf XB9R pistons that bump compression to 11.0:1. Next he shipped the stock muffler to Drummer Racing Products in the heart of North Carolina's NASCAR Country. Drummer guts the original muffler, deletes the heavy OEM muffler valve apparatus, and reassembles with a lighter, higher-flow core that delivers the flattest torque curve this side of Dale Jr.'s Impala. Then he plugged in Daytona Twin Tec's simple-but-effective Twin Tuner fuel-injection controller, which uses up and down push-buttons to let you quickly and easily trim the fuel mix.
Strapped to the Hal's Speed Shop dyno, the massaged motor put out 92 horsepower and 78 lb.-ft. of torque, a sizeable increase over stock. But peak numbers are just part of this story: The torque curve is a thing of beauty, one of those high and wide plateaus that only comes from a two-valve twin. Where the stock curve falls into a deep hole at 3500 rpm, the modded motor now produces a whopping 70 lb.-ft.-an 8 lb.-ft. increase, and equal to the stock bike's peak torque. Output climbs upward from there, and the difference in acceleration is night and day.