The Honda CBR600RR is a 599 cc Honda sport bike motorcycle that was introduced in 2003 as a race replica version of Honda's CBRFx series motorcycles.
Honda's middleweight sport bike underwent a complete and total redesign for 2007 with reducing the CBR600RR's weight as their primary focus. The result was a 20 lb reduction in dry weight over the 2006 model, from 361 lb to 341 lb.
In redesigning the CBR600RR for lighter weight and increased performance, Honda's R&D engineers started with the engine. The completely new engine is the smallest and lightest powerplant in the 600 cc class by a significant margin - its designers having used careful positioning of all internal components to achieve significant reductions in the motor's length, width, and height, as well as reducing weight by 2 kg (4.4 lb).