Sporting middleweights have always found starring roles within Honda’s range, thanks to the poise and usability produced by their combination of low mass and strong engine performance. In 2014, Honda bucked the trend toward higher capacity middleweights by introducing the CBR650R a true fourcylinder sporty middleweight that offers high style and specification, an involving easytouse riding experience and real value for money.
Based on the same platform as the naked streetfighterstyled CB650F, the CBR650F was designed by a young team of Honda engineers as a sportsoriented bike, usable and enjoyable in the real world by riders of all backgrounds and experience, in environments from busy urban streets to twisting back roads.
The double overhead camshaft (DOHC) 649-cubic centimeter fourcylinder engine powering the CBR650F is engineered to deliver high torque through the low-to-mid engine speed range, especially below 4,000 revolutions per minute.
The development team included many engineers in their twenties, selected to produce a bike with a focus on the younger customer. They decided early on that chasing peak power at redline was off their agenda. Strong acceleration from a standing start, low/mid range torque and midgear rollon throttle response were targeted as the essential elements.
Crisp pickup above 6,000 rpm and – for the sake of reduced running costs – economical cruising at highway speeds was also a focus. The engine is also designed to look good, with no external plumbing obscuring its lines. Sitting relatively far forward in the chassis for optimal weight distribution, the engine is truly at the heart of the machine.
The CBR650F’s steel twinspar frame has a tuned rigidity balance along with cast pivot plates and aluminum swingarm. The rear shock works directly on the swingarm and is matched to a 41-millimeter telescopic front fork; the wheels are a new sixspoke design. Twin 320-millimeter wavy front and a single 240-millimeter rear disc deliver the stopping power with twochannel anti-lock brake system fitted as standard.
A low center of gravity, slim feel and highset clipon handlebars give excellent control and confidence. And the CBR650F’s sharp lines are enhanced by an effective but minimal full fairing that shows off the engine to the maximum. An HRCinspired racing White, Red and Blue Tricolor paint option provides a finishing flourish.
The CBR650F’s liquidcooled engine uses compact internal architecture, stacked six speed gearbox and starter/clutch layout with the four cylinders canted forward 30 degrees. The DOHC 16valve cylinder head employs direct cam actuation and cam timing that equals strong torque performance and drivability below 4,000 rpm.
Bore and stroke is set at 67 millimeters x 46 millimeters. Optimization of conrod length has decreased the sideforce on each piston and “breathing” holes in the crankcase walls between the journals reduce pumping losses as engine speed rises. The pistons were developed with Computer Aided Engineering (CAE) and asymmetric skirts minimize bore contact and reduce friction. Ferrous spines on the outer surface of the cylinder sleeves reduce oil consumption with improved heat transfer.
Peak power of 86hp arrives at 11,000 rpm with peak torque of 63 Newton-meters at 8,000rpm. The engine is smooth at all engine speeds, with distinct inline fourcylinder character and resonance.
Internal water channeling from cylinder head to cylinders does away with a great deal of the exterior hoses normally required and the motor shows off its minimal, elegant beauty and functional style. The layout of the oil filter (behind the engine) and oil cooler (front left) plus internal oilways further enhance the visual appeal and has enabled use of an evocative right sideswept 421 exhaust.
To deliver good fuel economy at constant throttle, short valve overlap timing works with a specific ignition map; fuel consumption of 21 kilometers per liter (WMTC mode) gives an over 350-km range.