2025 Honda GB350S

Honda re-introduces the GB name to Europe. The A2-compliant GB350S is powered by a new air-cooled engine laden with character and satisfying torque. It also features an assist/slipper clutch and HSTC for added peace of mind. A steel semi-double cradle frame provides perfect feel, and combines with 41mm telescopic forks, twin rear shocks and 310mm front disc for easy handling. The clean and simple styling is classic Honda roadster, with steel fuel tank, resin side panels and front mudguard; all lighting is LED. The instrument display includes analogue speedometer and digital gear indicator.

1. Introduction 

The simple, universal appeal of a motorcycle.

That’s what Honda’s engineers were looking to capture when thoughts turned to developing the new GB350S. Using all the technology at their fingertips, their aims were to make a timeless, small capacity, single-cylinder, air-cooled engine that will perform in a modern environment both enjoyably and efficiently. And in doing so, create a bike that’s a real pleasure to ride, for every level of experience, delivering high quality engineering, timeless style and pride of ownership at a very affordable price point.

Honda have generations of experience building a bike for every rider. And with an ever increasing number of A2 licence bikes joining the market to attract a younger demographic to the joys of motorcycling, the time is right for Honda to add to its European range a bike that takes inspiration from models of the past, but has an eye very much on the future. The GB350S does just that.

It is a perfect bike to start – or continue – the two-wheeled adventure and enjoy everything it brings: the camaraderie, shared moments and new horizons. Whether a run for coffee with friends or further afield, the GB350S effortlessly achieves the goals set out for it, with authentic charm and an open book for any owner’s customisation desires.

Two wheels, handlebar, engine. Enjoy.

2. Model Overview 

Air-cooled, SOHC the 348cc HSTC-equipped engine produces 15.5kW peak power with 29.0Nm of torque, focussed in the low- to mid-range. But it’s also an engine – long-stroke, with heavy flywheel mass – tuned to feel exactly like a single-cylinder should, with character and sound that’s unmistakeable. The wide-ratio, five-speed gearbox is managed by assist/slipper clutch for fuss free gear changes.

The GB350S is a bike made to navigate busy city streets with ease. The steel semi-double cradle frame provides stable, confident handling, the overall geometry gives a tight turning radius; both centre of gravity and seat height are reassuringly low. 41mm telescopic forks and twin rear shocks provide supple suspension, with braking taken care of by 310mm front/ 240mmm rear discs and ABS control. Wheels are a 19/17-inch front and rear combination.

Deliberately understated styling pays homage to Honda’s illustrious roadster history with steel fuel tank, resin side panels and front mudguard, and stylish blacked out detailing on the engine and cycle parts. All lighting is LED, led by a circular headlight, while a compact analogue speedometer is at the centre of an attractive instrument display.

A range of genuine Honda accessories are ready to go for the GB350S, and include large and small saddle bags, a variety of screen options and engine side pipes.

The 25YM GB350S will be available in the following paint options:

• Puco Blue
• Gunmetal Black Metallic
• Pearl Deep Mud Gray

3. Key Features

    3.1 Engine 

Rich in character, the 348cc SOHC 2-valve air-cooled single-cylinder engine is a new design that, from the outset, looks to deliver soulful feel alongside engaging performance. The effort from Honda’s development engineers was to create the right ‘pulse’ from combustion energy and a high mass flywheel – which the rider very much feels as a pleasurable heartbeat – while minimising vibration. An extra main shaft coaxial balancer works in conjunction with the primary balancer for this purpose.

The air intake from the clean side of the airbox to the PGM-FI has designed to be straight,  with optimised diameter to reduce intake air resistance, and a pipe length to generate powerful torque from low speeds. For stable air intake, the port is located behind the airbox with an intake route that runs beneath the seat and across top of the airbox. This design contributes to the strong low rpm performance and ‘heartbeat’ of the engine.

The exhaust note was also factored in right at the start of development. The downpipe is double skinned while the muffler (chamfered for improved lean angle with 45mm diameter tail pipe) uses a single expansion chamber; the resulting sound is a distinct, characterful bass beat – just right for a single.

Peak power of 15.5kW is delivered at 5,500rpm with peak torque of 29.0Nm arriving low down in the rpm range at 3,000rpm. Its architecture is long stroke with bore and stroke set at 70mm x 90.5mm and compression ratio of 9.5:1.

And while it has a classic look, a host of Honda’s latest low-friction technologies – like a 10mm offset cylinder, asymmetric con-rod and sealed crankcases – are all built in to deliver optimum fuel efficiency. To achieve both oil capacity and reduced crankshaft oil mixing resistance in limited space, the sealed crankcase uses a bulkhead between the transmission chambers and crankcase.

A reed valve, located in the bulkhead opens and closes as crankshaft pressure fluctuates due to piston action, discharging oil from a piston jet (that cools the piston and lubricates the big-end of the con-rod). This is then passed into the transmission chamber, reducing friction thus improving fuel economy.

For optimum cooling efficiency the depth, thickness and spacing of the cooling fins has been carefully optimised. The work also adds to the engine’s presence and aesthetic. To cool the area behind the combustion chamber, an oil passage in the cylinder head covers the upper portion of the head, reducing temperature by 10%.

The five-speed gearbox uses wide gear ratios between first and fourth, to make the best use of the torque delivery around town, with fifth set for wide-ranging acceleration from 30km/low rpm up to cruising speed. An aluminium cam assist/slipper clutch reduces lever load by 30%, easing around-town riding and upshifts while controlling the rear wheel under braking and downshifting.

Honda Selectable Torque Control (HSTC) manages rear wheel traction, which adds confidence and peace of mind for all experience levels. The engine returns 40km/L (2.5l/100km, 94.1mpg) (WMTC mode); this gives a potential range of up to 600km from the 15L fuel tank.

3.2 Chassis

Fittingly, a classic steel tube cradle frame provides just the right look for the GB350S. It balances longitudinal, lateral and torsional rigidity and draws out the suppleness of steel for perfect feel. The rigid swingarm is constructed from 60 x 30mm box section steel, for efficient torque transfer.

Rake and trail are set at 27°/120mm, with 45mm fork offset and wheelbase of 1,440mm. Seat height is a very manageable 800m; kerb weight is set at 178kg and there’s 168mm ground clearance.

The steering geometry, low centre of gravity, low seat height and wide pull-back handlebars make for stable – yet easy – handling. A 43° steering angle delivers a 2.3m minimum turning radius, for urban manoeuvrability. 41mm telescopic forks offer 106mm stroke and, with an eye on classic details, wear protective black rubber gaiters. Twin rear shocks also deliver 120mm travel and are nitrogen gas charged for enhanced damping control.

A single 310mm front disc is worked by a newly designed, and highly rigid, twin-piston caliper, the rear 240mm disc by single-piston caliper. Long-life friction material is used for the brake pads; the compact ABS modulator simplifies the hydraulic system for the rear brake. Wheels are elegant 14-spoke cast aluminium; the front ABS pulsar ring is minimised to accentuate the slender spokes and the 19-inch front is matched to a 17-inch rear. Tyres are Metzeler Tourance Next sized 100/90-R19 front and 150/70-R17 rear.

3.3 Styling & Equipment

The GB350S’s outline is the very definition of a clean and simple Honda roadster, with straightforward, timeless style that harks back to the iconic designs of the past. The shaping of the fuel tank and resin side panels – and the proportion between them – are evocative, as is the low ‘tuck-roll’ seat profile. Matching nimble front and rear mudguards are quality finishing touches.

Features like the distinctive circular headlight – with three upper and centred lower LED bulbs – and eye-shaped LED indicators add hints of subtle modernity and a unique light signature. And the blackout detailing which includes the beautifully finished engine (with its polished cooling fins), headlight surround, fork legs, swingarm, exhaust downpipes, wheels and rear springs make the classic lines standout even more.

Straightforward instrumentation is provided by compact, analogue speedometer offset from the ignition; a digital gear indicator is included as well as average/instantaneous fuel consumption, distance to empty and ECO indicator.

The rear indicators also incorporate an Emergency Stop Signal (ESS) function. Under hard braking, the hazard lights flash to warn other road users a hard stop is in process. The indicators also auto-cancel; rather than using a simple timer, the system compares front and rear wheel speed difference and calculates when to cancel the indication relative to the situation.

4. Accessories

A full range of Genuine Honda Accessories are available for the GB350S either individually or in carefully curated packs for user convenience.

The Style Pack enhances the GB350S appearance by adding accessories that complement the iconic design cues of the model. The pack includes:

• Engine Upper Pipe – crafted with a robust 28.6mm extra-thick steel pipe, enhancing the GB350S’s bold aesthetic
• Single Seat Cowl – covers the passenger section of the seat to highlight sportiness and heritage styling
• Grip Ends – come with a unique mounting bolt, adding a stylish touch to the bars
• Head Light Cowl – provides both rider comfort by deflecting air and adding a further sporty touch to the front of the bike
• Side Tank Pads – adding protection to the fuel tank and improve riders’ grip
• Fog Lights – operated through an integrated handle switch.

The Travel Pack offers additional storage space, improves comfort, convenience and practicality on longer journeys. The pack includes:

• Saddle Bags & Supports – 14L left & 10L right, made of sturdy ballistic nylon and easily detachable for added convenience.
• Knuckle Guards – minimizing wind and rain impact on the rider’s hands and arms
• Long Visor – with 355 mm of height, deflects travelling air away from the rider’s head and shoulders.

The line-up is completed with optional Heated Grips (with five heat levels of adjustment), a practical USB charger and a Meter Visor (short version of the long visor).

All the accessories featured in packs can also be purchased individually.

5. Technical Specifications

All specifications are provisional and subject to change without notice.

# Please note that the figures provided are results obtained by Honda under standardised testing conditions prescribed by WMTC. Tests are conducted on a rolling road using a standard version of the vehicle with only one rider and no additional optional equipment. Actual fuel consumption may vary depending on how you ride, how you maintain your vehicle, weather, road conditions, tire pressure, installation of accessories, cargo, rider and passenger weight, and other factors.

For more Honda Motorcycles UK news check out our dedicated page Honda Motorcycles UK News

or head to the official Honda Motorcycles UK website honda.co.uk/motorcycles.html

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