Slim & Compact Configuration
Specially designed to be slimmer and easier to handle than the vast majority of scooters in the mid-displacement class, the SH300i’s overall length is only 3% longer than that of its smaller-displacement predecessor, the SH150i/SH125i. One of the lightest, narrowest and most compact models in its class, the SH300i establishes a new direction in scooter design and function, providing exceptionally comfortable riding ease combined with its impressively strong power delivery and crisper, more sporty handling.
Like its predecessor, the SH300i’s most distinctive design features include:
a) Slim proportions, especially compared to other scooters in its displacement class,
b) Spacious flat floorboard area for easy mounting and dismounting and enhanced leg and foot manoeuvring ease while on the move and
c) Big, motorcycle-like 16-inch (40.6cm) diameter wheels mounted with wide, low-profile tyres, which provide a smooth and confidently assured ride that compares more favourably to a real motorcycle than do the much smaller wheels found on many other scooters.
d) Easy-mounting 785mm seat height, which provides an ideal balance of optimal rider eye level and comfortable seating with a relatively easy reach to the ground thanks to its narrow proportions.
The SH300’s fuller, more elegantly curvaceous scooter styling comfortably surrounds the rider, and is highlighted in front by a large clear-lens multi-reflector headlight designed to provide maximum illumination over a wide area for excellent night-time visibility. The sleek front bodywork also incorporates distinctive clear-face front indicators with amber bulbs into its smooth design, which also feature ever-on position lamps positioned behind clear plastic lenses which work together with the headlight to enhance visibility and ease other motorists’ judgement of the vehicle’s distance and approaching speed. At the rear, a fully integrated tail-light and rear indicator assembly.
The new SH300i is powered by an all-new liquid-cooled, fuel-injected engine which produces the highest performance and strongest acceleration in its class. Not merely a larger displacement version of an existing design, the SH300i’s advanced power unit was uniquely developed and crafted to meet its specific needs, and packed with design features and technologies developed in the racing world and then adapted to this next-generation scooter.
Advanced Honda Racing Technology for the Smallest Engine in the 250cc Scooter Class
The SH300i’s newly developed 279cm3 SOHC 4-valve engine borrows much of its highly advanced technology from Honda’s famous CRF series of motorcross racers, which are powered by some of the most compact, lightweight and
highly competitive engines in their respective classes. In particular, its innovative sealed crankcase configuration, directly influenced by Honda’s high-performance CRF engine design, makes possible much smaller and more
compact dimensions than any single-cylinder scooter engine in its class.
Besides being the most compact scooter engine ever developed in its displacement class, the SH300i’s new sealed crankcase engine design also maximises power output by minimising internal resistance losses.
Internal Resistance Minimised For Stronger Power
Unlike most wet sump engines, the SH’s crankshaft never comes into direct contact with the engine’s reservoir of oil. This eliminates the occurrence of power-robbing windage, which results from the crankshaft contacting the upper
surface of the oil sump and churning it into a dense foam. Instead, the SH300i’s engine oil is held inside a separate chamber within the engine, and lubricating oil circulating within the crank cavity is quickly evacuated through a one-way reed valve leading back to the oil reservoir cavity with each rotation of the crankshaft. This elimination of oil windage results in significant improvements in power production, quicker acceleration and a major contribution to the SH300i’s excellent fuel economy.The engine’s sealed crankcase design also allows the oil reservoir to be positioned for the most compact dimensions, and even allows its oil pan to be raised for ample ground clearance while lowering the engine’s centre of gravity.
Reduced Crankcase Air Pressure
The SH300i’s new engine was also designed to minimise power losses associated with air pressure build-up within its compact crank cavity. As an engine’s piston falls on the intake and power-producing combustion strokes, the air inside the lower crankcase compresses, causing air pressure resistance or pumping loss that
Floating Link System Composition
The SH300i’s three-piece articulating floating link system hangs from a single pivot point under the back of the lower frame. A large yoke section reaches directly back from the first pivoting hanger and surrounds the
engine’s unit swingarm pivot. Finally, reaching up from the swingarm pivot is a short swing rod, which connects directly to the side of the engine by way of large vibration-damping rubber bushings.
The combination of these three linked and articulating joints permits a measured degree of free fore-and-aft engine and swingarm movement that minimises the transmission of rear wheel shocks and vibration to the frame.
It also effectively isolates most of the engine’s primary vibration, which is generated along the same longitudinal axis.
Rubber bushings used in the attachment of the vertical swing rod to the engine also permit a small amount of vertical engine and swingarm pivot movement that helps damp out vibration in this axis as well.
In the horizontal axis, however, the floating link system’s combination of three linked parallel pivot points, which utilise both needle roller bearings and rubber bushings, provides a solid brace against the twisting
lateral movement of the unit swingarm to ensure excellent lateral and torsional rigidity that results in remarkably precise and confident handling control, even while allowing a degree of free fore-and-aft movement.
This new floating link system also has the added benefit of lowering the height of the swingarm pivot compared to conventional scooter unit swingarm designs, thus permitting the SH300i’s dual-damper suspension system to more
effectively absorb the vast majority of vertical swingarm movement, rather than allowing it to be transmitted through to the frame through a higher pivot point geometry, resulting in smoother and more stable handling.
Another contributing factor to the SH300i’s precise and responsive handling is its smoothly compliant suspension systems. Up front, a sturdy motorcycle-type 35mm- diameter telescopic fork like that featured on all of
Honda’s latest high-performance scooters provides smoothly responsive bump absorption combined with swift and sure control, while a pair of dual conventional dampers take up duty in the rear to complement the new floating link swingarm pivot with 95mm of progressive damping for a pleasantly smooth and controlled ride, as well as remarkably sporty
tracking and cornering control. Featuring 5-step adjustable spring preload, these dampers enhance riding confidence and high-speed handling, especially when fully loaded with a passenger and carrier-mounted top box.
Like its smaller predecessor, the SH300i rolls on large, lightweight 16-inch- diameter cast aluminium wheels. Both feature a distinctive 6-spoke pattern that complements SH’s slim, attractively curved bodywork for a look of elegant urban style. These wheels also mount wide-bodied, low-profile 110/70–16 front and 130/70–16 rear tubeless tyres that provide sure, responsive control and enhance riding comfort over virtually all road
surfaces and riding conditions the new SH300i may encounter.
Easy-Operation Combined Brake System
Like many others models in Honda’s extensive motorcycle and scooter lineups, the SH300i comes fully equipped with Honda’s exclusive Combined Brake System, which links its front and rear disc brakes together for an optimised
balance of braking control that significantly enhances riding confidence.
This well-proven system featuresa single Combined three-piston front brake calliper gripping a
large-diameter 256mm rotor between sintered metal pads for reassuringly strong braking control.
At the rear, a compact single-piston calliper stops another 256mm rotor.
Like most conventional motorcycle brake systems, the right-side brake lever controls the two outer pistons of the three-piston front brake calliper to provide strong and sure braking control. The left-side brake lever,
however, not only controls the rear brake, it also directs a carefully regulated level of braking force to the centre piston of the three-piston front brake calliper by way of a delay valve. This system thus provides a more efficient and smoothly controlled balance of front and rear braking forces when only the left-side lever is used. In operation the rear
calliper engages first, followed soon thereafter by the engagement of the front calliper, for a more smooth
and effective range of braking response. When both levers are used, the SH300i provides a smoothly responsive balance of braking control that brings it to a swift and calmly assured stop.
Sleekly Styled Instrument Panel
The SH300i’s attractive, large-face instrument panel is cleanly and elegantly integrated into the top of its steering head, and features a more precise and minutely detailed design that provides a constant reminder of Honda’s unerring attention to the smallest detail. Its large, easy-to-read central speedometer is surrounded by coolant temperature and fuel gauges, and the whole assembly is recessed behind an attractively styled, resin-framed clear plastic lens. Indicator lights and a large LCD digital clock and dual-trip meter are positioned in easy view atop the handlebars.
Honda Ignition Security System (HISS)
Like most late-model Honda motorcycles and top line scooters, the SH300i features the highly effective HISS anti-theft security to ward off potential thieves and joyriders by preventing the engine from being started by any other than its
two original keys. Since HISS disables the engine at the heart of its ignition system, it cannot be bypassed by either hot-wiring the ignition or exchanging the ignition switch module,
thus rendering impossible one of the most common types of vehicle theft, that of being ridden away.
Under-Seat Carrying Space
Like the SH150i/SH125i before it, the SH300i features a compact carrying space under its locking tilt-up seat which opens at the turn of the ignition key and offers welcome carrying convenience and a secure place to store one’s helmet. Designed to hold one of the wide variety of popular stylish ‘semi-jet’ helmets available, this space also provides ample room for other travelling essentials, as well as a bit of light shopping whenever the need arises.
Up front, a slim locking glovebox opens to offer space for such small essentials as gloves, papers and other articles, and even features a utility socket for charging or powering such electrical accessories as a mobile phone. Shopping bags and other bulky items with handles or straps can be easily and securely hung in front, between the rider’s legs, from a convenient spring-loaded carrying hook.
Compact Rear Carrier
Behind the SH300i’s spacious seat sits a compact moulded resin rear carrier that doubles as a comfortable hand grip for pillion passengers. As featured on its smaller sibling, the SH150i/SH125i, this carrier is specially designed with moulded-in attachment points to allow for quick and easy mounting of a specially designed and colour-matched 35-litre top box (optionally available), which quickly and easily clips directly onto the carrier and can be secured with a key. No other mounting hardware is required.
Specifications SH300i (ED-type)
Type Liquid-cooled 4-stroke 4-valve SOHC single
Bore x Stroke 72 x 68.5mm
Compression Ratio 10.5 : 1
Max. Power Output 20kW/8,250min-1 (95/1/EC) Max. Torque 26Nm/6,000min-1
(95/1/EC) Idling Speed 1,500min-1
Oil Capacity 1.7 litre
Carburation PGM-FI electronic fuel injection
Throttle Bore 34mm
Aircleaner Dry, cartridge-type paper filter
Fuel Tank Capacity 9 litres
Ignition System Digital transistorised with electronic advance Ignition
Timing 10° BTDC (idle) ~ 28° BTDC (8,250min-1) Sparkplug Type LMAR8A-9
Starter Electric Battery Capacity 12V/11AH ACG Output 368W
Headlight 12V, 55W x 1 (low) / 60W x 1 (high)
Clutch Type Automatic; centrifugal
Transmission Type V-Matic
Belt Converter Ratios 2.350 ~ 0.800
Final Reduction 8.571
Final Drive V-belt
Type Underbone; steel tube
Dimensions (LxWxH) 2,100 x 730 x 1,220mm
Wheelbase 1,420mm Caster Angle 27° 30' Trail 98mm
Seat Height 785mm
Ground Clearance 136mm
Dry Weight 161.8kg *164.7kg
Kerb Weight 169.1kg (F: 65.3kg; R: 103.8kg)
*172kg (F: 68kg; R: 104kg) Maximum Carrying Capacity 180kg
Loaded Weight 319kg (F: 101kg; R: 218kg)
*322kg (F: 103kg; R: 219kg)
Type Front 35mm telescopic fork, 102mm axle travel
Rear Dual-damper unit swingarm, 95mm axle travel
Type Front U-section 6-spoke cast aluminium
Rear U-section 6-spoke cast aluminium
Rim Size Front 16 x MT2.75
Rear 16 x MT3.50
Tyres Front 110/70–16 52P Rear 130/70–16 61P
Tyre Pressure Front 200kPa
Rear 225kPa (with passenger:225kPa)