Honda CB 750 K (RC01)
 Honda CB 750 K | |
| Manufacturer | Honda |
|---|---|
| Production | 1978-1982 |
| Predecessor | CB750 Four |
| Successor | CB 750 K (A) CB 750 K (B) CB 750 F |
| Class | Sport bike or standard |
| Engine | 743 cc (45.3 cu in) DOHC air-cooled straight four[1] |
| Top speed | 125 mph (201 km/h)[1] |
| Power | 58 kW (78 hp) @ 9000 rpm[1] |
| Torque | 49 lbf⋅ft (66 N⋅m) @ 7000 rpm[1] |
| Transmission | 5-speed manual, chain final drive[2] |
| Suspension | Front: telescopic forks Rear: swingarm with two spring/shock units.[2] |
| Brakes | Front 275 mm double disc / Rear 180mm drum[2] |
| Wheelbase | 1,520 mm (60 in)[1] |
| Dimensions | L: 2,200 mm (87 in)[1] W: 880 mm (35 in)[1] H: 1,160 mm (46 in)[1] |
| Seat height | 800 mm (31 in)[3] |
| Weight | 233 kg (514 lb)[1] (dry) |
| Fuel capacity | 20 L (4.4 imp gal; 5.3 US gal)[1] |
| Fuel consumption | 7.3 L (1.6 imp gal; 1.9 US gal) per 100 km (62 mi)[2] |
The CB 750 K(Z) (model RC01) is a motorcycle model by the Japanese vehicle manufacturer Honda.
The new 750[edit]
At the 1978 IFMA in Cologne the new CB 750 was presented as the successor to the CB 750 four for Europe and available for sale later that year. With a new DOHC engine design and numerous other new features it was presented as "what happens when you keep winning races".[4]
New features[edit]
The DOHC 16 valve engine was based on the engine in the RCB943 and RCB997 featuring four valves per cylinder, and next to the timing chain driving the exhaust cam, a second chain driving the intake cam. [5] The engine was also better balanced by moving the alternator from the left to the right side. [6]
Next to the new engine, new features like the transistorized ignition system was promising smooth performance and greater economy. It had increased braking performance with double discs up front and a lower, deeply padded seat for greater riding comfort and handling. Increased suspension travel for the front forks and rear FVQ damper, and a taper roller bearing for the head for smoother riding. Improved safety features like an H4 headlamp and double rear brake light bulbs were also advertised.[4]
Technical details[edit]
Engine and power transmission[edit]
- Air-cooled 4-cylinder 4-stroke engine with chain driven camshaft (DOHC), 4 valves per cylinder (total of 16), via tappets actuated
- Power: 57 kW (77 hp at 9,000 min -1 .), Max torque 66 Nm at 7000 min -1
- Average piston speed : 2.07 m / s per 1,000 min −1
- Top speeds: 200 km / h (lying solo), 187 km / h (sitting solo), 179 km / h (with pillion passenger)
- 743 cm³ displacement with 62 mm (2.4 in) bore and 62 mm (2.4 in) stroke
- Compression ratio 9: 1
- Electric starter
- Contactless transistor-controlled battery ignition with mechanical centrifugal force adjustment
- Pressure circulation lubrication
- One-piece steel crankshaft with 5 sliding bearings
- 4 Keihin equal pressure carburetors with a diameter of 30 mm (1.2 in)
- Wet multi-plate clutch
- Constant-mesh 5-speed gear
- Three-phase - alternator (260 Watt at 5000 min -1 ), battery (12 V / 14 Ah)
- 4-in-4 exhaust system (sometimes shown as 4-in-2-in-4)
- Primary drive via inverted tooth chain
- Secondary drive via roller chain
Frame[edit]
- Double-loop tubular steel frame with a single-sided unscrewable support on the right for (dis) assembly of the motor
- Rear swing arm stored in plastic bushings (needle roller bearings from the end of 1980)
- Ground clearance 150 mm (5.9 in)
- Foot peg height 355 mm (14.0 in)
- Hydraulically damped telescopic fork at the front (35 mm (1.4 in)) with 160 mm (6.3 in) travel
- 2 hydraulically damped spring struts at the rear, springs adjustable in 5 positions
- Double 275 mm (10.8 in) disc brake with single-piston calipers at the front
- Simplex drum brake 180 mm (7.1 in) at the rear
- Comstar aluminum wheels with tubeless tires (3.25-19 / 4.00-18)
- 20 L (4.4 imp gal; 5.3 US gal) steel tank
Colors[edit]
The CB 750 K (Z) was available in four base colors: blue, black, red and brown.
| Color code | Name | Implementation |
|---|---|---|
| R-104C-U | Candy Muse Red/Candy Burgundy | Metallic paint with gold or light red striping |
| YR-106C-U | Candy Bayard Brown | Metallic brown with gold striping (Canada only) |
| PB-107C-U | Candy Tanzanight Blue | Metallic blue with gold striping |
| NH-1 | Black | Black with red striping |
References[edit]
- ^ a b c d e f g h i j k "Launched Honda CB750K, a large 4-cylinder two-wheeled vehicle with "comfortable driving" and "light maneuverability"", Honda press release, December 12, 1978
- ^ a b c d e Honda CB750K Service Manual, (Honda Motor Co., Ltd.), 1978
- ^ Honda CB750 & CB900 dohc fours 1978 to 1984 Owners Workshop Manual, Haynes_Manual, 2015, ISBN 978-1-85010-217-5
- ^ a b Ker, Rod (2015), Honda CB750 four, Amberley_Publishing, ISBN 978-1-4456-5121-7
- ^ "Honda Comes Back Strong". Cycle World. January 1, 1979.
- ^ "Honda CB750K, A Sophisticated Successor to Honda's Traditional 750". Cycle World. January 1, 1979.