Honda CBR400RR

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Honda CBR400RR
Manufacturer	Honda
Also called	"CBR400", "BabyBlade"
Production	1988 - 1999(?)
Class	Sportbike
Engine	Liquid-cooled, four-stroke inline-4 cylinder, gear-driven DOHC, 4 valves per cylinder
Power	~55 bhp (standard output)
Transmission	6-speed manual; chain drive
Suspension	41mm oil-damped Showa forks (front); gas-damped single shock absorber (rear)
Brakes	double-disc with 2-piston Nissin calipers (front); single-disc with 1-piston Nissin caliper (rear)
Tires	Bridgestone BT-090 or similar
Wheelbase	1370mm (-J); 1380 (-K); 1365 (-L, -N & -R)
Fuel Capacity	15 litres
Similar	Honda VFR400, RVF400, NSR400; Kawasaki ZXR400; Yamaha FZR400; Suzuki GSXR400

The Honda CBR400RR, or 'BabyBlade', is the (much) younger brother of the Fireblade or CBR900RR series. The CBR400RR preceded the 900cc Fireblade by several years, going through one major rework and a year or so of production in its new form before acquiring the Fireblade name. The original CBR400RR was the NC-23. Early bikes were known as the 'Aero' but more commonly as the 'Tri-arm' after its racing inspired braced swingarm. The CBR400RR-J (1988) and CBR400RR-K (1989) are referred to as NC-23 bikes^[1]. The NC-23 has a standard extruded beam frame, the rear of the seat unit slopes forwards, and the seat unit subframe is totally separate from the main chassis of the bike. The later machine, the NC-29 (only post '92 models of this bike carry the the Fireblade name) had several modifications to the frame. The main rails were now of a 'cranked' design, the seat support structure had a larger rail that was welded to the frame, the rear of the tail section now had a slight recurve to it and the swingarm was given a gull-wing shape on one side to give ground clearance for the exhaust link pipe. The bodywork was re shaped to comply with changing asthetic tastes. That reshaped swingarm earned the bike the sub title 'Gullarm'. The CBR400RR-L (1990 & 1991), -N (1992 & 1993) and -R (1994 onwards) are designated NC-29 bikes^[2].

Developed mostly for younger Japanese riders, the 400cc engine still has enough power to drive the bike up to a speed-limited 180km/h (112mph). It is possible to de-restrict this bike by re-wiring the speedometer head, as the speed-limiter is a simple design based solely on the position of the needle of the speedometer. Aftermarket electronic parts can also be fitted that achieve de-restriction. The same effect can be achieved by fitting a mechanical converter on the speedometer cable that converts the Japanese spec km/h speedometer to mph; the bike is not powerful enough to accelerate to 180 mph, and thus the needle will never reach the position at which the ignition restrictor begins operation. De-restricted, the CBR400RR will reach a top speed of around 225 km/h (140 mph). The inline four cylinder engine produces pleasing power anywhere in its rev range, and the bike is light and relatively easy to control. Outside Japan the 400 is available only as a 'grey import', that is, Honda never exported the 400cc CBR to foreign markets. The small capacity of the engine and manageability of the whole package makes this bike a favourite of new riders from all areas where the bike is available. This does mean however that many examples have been crashed or treated without proper care and regular servicing. Servicing is in some ways difficult as the compact nature of the bike means that some parts, particularly the spark plugs are difficult to access. The top end of the engine is also particularly complex as there are 16 valves to be checked for clearance in a head that is barely a foot wide. However the engine itself is very reliable, mainly due to its performance being capped from the factory. A well kept example is a very worthy buy as they are rapidly becoming a collector's bike.

Common rider modifications include:

Fitting aftermarket exhausts;

Removal of the speed-limiter;

Restriction of the power output (for UK riders who have not taken a direct access course and are limited to 33bhp for two years on passing their full test);

Alterations to the suspension settings;

Fork changes to the upside down parts from the Honda RVF400.

The engine from the NC-23 was later used in the Honda CB-1, the NC-27, a naked bike that is credited with inspiring the popular Honda 'Hornet' range. However the NC-27 bears little mechanical resemblance to those machines and is probably the first true factory streetfighter.

[edit] Notes

1. ^ Coombs, M: "Honda CBR400RR Service and Repair Manual, p.p. 08, Haynes Publishing, 2005
2. ^ Coombs, M: "Honda CBR400RR Service and Repair Manual, p.p. 08, Haynes Publishing, 2005

[edit] See Also:

Japanese-language Official Honda CBR400RR Page