Team Obsolete’s Harley-Davidson XRTT 909 | Battle Axe

Some of the best roadracing action of the 1980s occurred in the AMA’s aptly named Battle of the Twins (BoTT), a catch-all category featuring the era’s most colorful and charismatic twin-cylinder racing machines in head-to-head competition. Starting as a one-off event at Daytona in ’81, BoTT became a legitimate class in ’82 and soon attracted an international field of riders on quasi-factory efforts from Ducati, Moto Guzzi, Harley-Davidson and more.

One of the most iconic—though not necessarily the most successful—of those early BoTT racers was Team Obsolete’s orange-and-black Harley-Davidson XRTT 909, ridden by Dave Roper. Team Obsolete was club racing the already outdated 750cc XRTT on the East Coast—with back-door support from Harley-Davidson’s racing department—when the first BoTT event was announced. Team owner Rob Iannucci decided to participate, and contacted H-D race boss Dick O’Brien to craft a plan of attack. O’Brien made some quick calculations and discovered the old iron-head XR750 flywheels, along with larger pistons from an abandoned overhead-cam Sportster prototype, yielded a 909cc engine that could be competitive in BoTT.

Famed Harley tuner Jim Belland built the first 909 motor with parts supplied by O’Brien, including heads, cams and carbs off Jay Springsteen’s factory dirt-tracker. Team Obsolete also sent the XRTT chassis to Belland, who altered the geometry, lowered the engine mounts and added an adjustable box-section swingarm. Team Obsolete designed the unique under-engine oil tank, relocated from its original location beneath the saddle to improve airflow around the rear cylinder.

Team Obsolete enthusiastically campaigned the 909 for two seasons. Roper led races at Daytona and Laguna Seca, but Iannucci says his limited tuning expertise hampered their success. The team eventually abandoned the Harley in favor of more user-friendly Ducatis, but Harley continued the effort, using lessons learned to develop “Lucifer’s Hammer,” the legendary, Don Tilley-tuned XRTT that Gene Church rode to three consecutive itles from 1984-’86.

Iannucci restored the original 909 to running condition last year, with assistance from Tilley and Carl Patrick. The revitalized racer, which hadn’t run since ’83, was revealed at last summer’s AMA Vintage Motorcycle Days. Roper got back in the saddle for a series of wide-open “parade laps” around the Mid-Ohio Sports Car Course, to promote the AMA’s new Vintage SuperTwins class created specifically to attract these legendary BoTT racers out of retirement.

Iannucci still has fond BoTT memories. “There was so much camaraderie,” he says. “The competition was friendly, and there was a lot of experimentation in the design of the bikes.” He was also happy for the opportunity to revisit Project 909: “This bike was unfinished business. When I built this thing the first time, I was at the beginning of a long learning curve. Now, I’m at the tail end. I think we built a much better bike this time around.”

Team Obsolete’s XRTT 909 served as the prototype for “Lucifer’s Hammer,” the three-time champion that was perhaps the most successful Harley-Davidson roadracer ever.