Wikipedia
The Honda CBR models are a series of sport bikes several of which (400RR, 600RR, 900RR, 929RR, 954RR and 1000RR) are marketed as race replicas, having the suffix RR after the engine size designation. With the exception of the single cylinder CBR125 and CBR150, all CBR motorbikes have inline engines (as compared to the V-twins in the VT, VTR and VF/VFR series). Less sporting models with inline engines make up the CB Series.