Yamaha had a great starting point with the R1, which has been so popular following its revamp two years ago that it's become the best-selling liter-size sportbike, with 50,000 units sold worldwide. Even so, the standard R1 has itself been revised for 2006, though the only tuning mods to the 998cc 20-valve engine are 5mm-shorter intake valve guides that reduce friction and boost airflow through better-breathing reshaped intake ports, plus recalibrated fuel and ignition maps in the 32-bit Mitsubishi ECU. Yamaha says those relatively subtle changes generate an extra 3 bhp, raising claimed peak power to 175 bhp at an unchanged 12,500 rpm (redline is similarly unaltered at 13,750 rpm). Peak torque bumps up from 77 to 80 pound-feet, the maker says. The tuning-fork firm also gave the engine a new camchain tensioner, a 5mm-longer mainshaft, and minor changes to the clutch and primary cover that improve oil circulation to the six-speed transmission. Of course, the LE model shares all of these changes.