With the homologation approval period for its limited-production RC45 coming to an end in '99, Honda surprisingly announced that it would be introducing a new liter-size V-twin superbike in its upcoming 2000 model lineup to run alongside the then-new CBR929RR inline-four superbike. With four-cylinder machines still limited to 750cc in superbike racing, it was an obvious sign that Honda was dumping the multi-cylinder route and looking to take on Ducati at its own twin-cylinder game. HRC (Honda Racing Corporation, the racing arm of Honda Japan) played a major role in the design of the new twin, which was designated the VTR1000 SP1 everywhere in the world except the U.S., where it was known as the RC51 (even though its actual model designation was RVT1000R).
In its first year, the Honda RC51 proved its performance potential by winning the '00 World Superbike title with Colin Edwards aboard. Meanwhile in the AMA Superbike series, a young Nicky Hayden just missed out on the title to Mat Mladin by a slim five points. Edwards grabbed another world title in '02, and Hayden would pick up a win in the Daytona 200 in his march to the '02 AMA Superbike championship.
The bike was an instant hit with sportbike fans. The RC51's booming exhaust note had a sound different than the Ducati twins, and surely unlike any other Japanese bike in production. The bike's HRC heritage could be seen throughout its design and was proudly displayed on the engine cases. And not only did Honda make a works racing replica machine, they offered it at a very affordable $9999. Compared to the very limited production RC45 ($27,000), this Honda was a bargain and they were snatched up across the country. Although import quantities couldn't quite be considered production-level, it's rumored that about 2000 were brought into the U.S.A. in the first year.
The aforementioned HRC design influence is reflected in the RC51 engine's architecture. As with the RC45 V-four before it, the 90-degree V-twin boasted gear-driven camshafts, an arrangement that provides more precise cam timing for better horsepower but is also very expensive to produce. Bore and stroke measurements were a then-very oversquare 100mm x 63.6mm configuration, although curiously with a relatively low compression ratio of only 10.8:1 (the Ducati 996 was pushing 11.5:1, while the Aprilia RSV Mille was at 11.4:1, and even the Suzuki TL1000R was bumping 11.7:1). With such a large bore, big valves could be installed, and Honda obliged with 40mm intakes and 34mm exhausts (for comparison, the Ducati 996 only had 36mm intakes/30mm exhausts). Even the engine fueling system was racing-spec; the Honda PGM-FI used a pair of 54mm throttle bodies-all of its twin-cylinder competition at the time of its introduction used smaller units-with 2 injectors per cylinder (all the others only had a single injector per jug). Due to the long-term reliability concerns of extended high-rpm running with a big V-twin (the cases undergo tremendous stress at five-figure rpm levels), the RC51 was saddled with a relatively low 10,000-rpm redline, with the rev-limiter stopping the party shortly thereafter at 10,200 rpm. In addition to the restrictive stock mufflers, the artificial rpm limitation kept the bike in showroom form down to about 118 horsepower at the rear tire.