Honda GB350S (2025) – Review

Technical Review - Ben Purvis, Nov 24
Riding Review - Steve Rose, Mar 25

It's been a long time since a 20hp, air-cooled, single-cylinder Honda has been so eagerly awaited. But the GB350S – hitting the European market at last after several years on sale in other regions – has already proved a surprise hit as it cashes in on the rampant popularity of similar machines.

Affordable, simple bikes in the 300-400cc class have been flying out of showrooms over the last few years. In the UK market Triumph’s Speed and Scrambler 400s sold 3000 units in 2024, winning the hearts (and wallets) of young riders on the way up through biking and older ones downsizing to a more manageable and affordable machine. The market for these easy-riding bikes has continued to grow even while overall motorcycle sales have contracted.

Pros & Cons

2025 Honda GB350S - Price

Honda has been showing a remarkable ability to undercut the competition with its new bikes over the last few years – with machines like the CB750 Hornet, Transalp and the new CB1000 Hornet all surprising with their combination of a low RRP and relatively high specification. The further down the market you go the more the more difficult it becomes to undercut rivals but Honda’s GB350S is doing its best to repeat the feat by coming in at £3949 when it arrived in dealers in January 2025.

That puts it as close as makes no difference to its nearest rival, the £3899 Royal Enfield HNTR 350, and substantially undercuts the Enfield Meteor 350 or Classic 350 models. Triumph's Speed 400 is £1250 more and their Scrambler is almost £2k more expensive. Given the sales success of all those machines in recent years, Honda is well placed to cash in.

On PCP finance with a £599 deposit you'll pay just £59 a month for 43 months and a final payment of £1650 to own the bike. Whether this is the kind of bike you'll keep for that long depends on whether you are on your way up through biking (where you might fancy something a little quicker after a couple of years) or coming back down.

Three colour options are on the table, a pale ‘Puco Blue’, the pearlescent ‘Deep Mud Grey’ or a metallic black.

2025 Honda GB350S - Engine & Performance

If you want to rebel against the sheer weight of technology that packs most modern bikes then the GB350S might be just the machine you’re after. Its spec sheet reads like something from an earlier century and shows that you don’t need all those gizmos to create an engine that’s fuel-efficient and eco-friendly. You just need to enjoy taking life at a more sedate pace.

With just a single cylinder, one overhead camshaft, two valves and a capacity of 348cc, the GB350S’s air-cooled motor even manages to look genuinely retro thanks to its near-vertical, finned cylinder. Only the emissions sensor sticking out of the top of the exhaust gives the game away that it’s a modern design, created specifically for this model.

It’s clear from the outset that performance wasn’t high on the priorities list, and Honda emphasises that the motor was designed for low and mid-speed torque rather than outright power. If the fastest things you've ridden is a 125cc bike, it'll still feel quick and torquey.

On the road it feels easy, confident and reassuringly docile. A heavy flywheel helps, as well as a coaxial secondary balancer to smooth out the delivery. First gear is short enough to get away ahead of the cars, but the downside is that you'll need to grab second before 20mph or you'll bump into the rev-limiter. Third and fourth gear are perfect for pretty much any town work and open roads up to a little over 60mph. And that's when things get interesting.

Top gear (there are only five) is very tall and if you're above 60mph in top with a slight headwind or uphill gradient you'll struggle to accelerate at all. The throttle ends up wide open and you go no faster. Drop down to fourth and there's plenty of acceleration from 60mph to beyond 70mph making top gear really just a cruising overdrive on 60mph roads.

Clues to the modern origin of the motor can be found in the fuel injection system – mounted on an intake that’s again designed for low-end torque rather than power – and the use of low friction tech that includes a cylinder that’s offset 10mm to reduce side-thrust of the piston during the power stroke. If that's not geeky enough for your retro-single how about an asymmetric conrod and a sealed crankcase with a bulkhead to separate the crankcase from the transmission? Or maybe a reed valve in that bulkhead which opens and closes as the piston moves and the pressure underneath it changes at which point an oil jet cools the piston and lubricates the big-end bearing. Oil is also used to strategically cool hotspots in the cylinder head, aiding the air-cooling and reducing temperature in that part of the head by 10%. Inside that head, the compression ratio is a mere 9.5:1. You can relax now, that's enough tech for one review.

While the peak power is only 20.8hp, it comes at a mere 5500rpm, and the max torque of 21.4lbft arrives at just 3000rpm. The rider has no idea, of course because there isn't a rev counter, only a limiter that cuts the ignition at high rpm. The low-revving nature is because the engine swaps the idea of ‘oversquare’ bore and stroke dimensions – typical in most modern bikes, where the cylinder bore is greater than the piston stroke to encourage more revs and more power - for a hugely under-square design with a 70mm bore and a 90.5mm stroke. This puts the emphasis on torque, at the expense of revs and power. Even the Royal Enfield HNTR 350, another bike with an under-square engine, doesn’t take the dimensions to that extreme, using a 75mm bore and 85.5mm stroke  to achieve a similar capacity to the Honda. The CB350S’s peak power and torque figures are a whisker higher than the Royal Enfields but arrive substantially lower in the rev range thanks its more extreme under-square dimensions.

The retro cues don’t end with the air-cooled engine. It drives a gearbox with only five speeds, albeit through a modern-seeming assist/slipper clutch. Somewhat surprisingly, there’s even traction control as standard.

2025 Honda GB350S - Handling & Suspension (inc. Weight)

The steel cradle frame of the GB350S is just as retro as its engine, with a twin-shock rear end and right-way-up forks clad in old-school gaiters.

Honda claims that the chassis has just the right balance of rigidity and suppleness, and the geometry leans towards stability rather than rapid responses. A rake of 27 degrees is certainly towards the relaxed end of the spectrum, and the 1440mm wheelbase is substantially longer than either the Speed 400 or the HNTR 350, which both come in at around 1370mm or so.

After riding it, we think Honda have done a good job. The GB350 steers easily and accurately, with enough agility to feel exciting, but confidence too to help novice riders work out how to steer a bike properly. That long wheelbase doesn't feel cumbersome but helps the bike remain stable in bumpy corners.

The forks are 41mm in diameter and offer 106mm of travel but no adjustability, while the twin shocks are nitrogen filled and give 120mm of wheel travel. Hit a big bump at higher speeds and the back wheel kicks out of line while the bars flap as the soft suspension gets overwhelmed. On slower, bumpy lanes where you'd normally only take an adventure bike, the Honda takes everything in its stride. Having a friendly, upright riding position, gentle power delivery and well-balanced chassis helps here too. As with most things about this bike, the key to enjoying it is to understand that it works at a slower pace of life. That's a good thing by the way, because, like a Harley, the GB350S offers an enjoyable alternative to head-down motorcycle rock and roll (other cliches are available).

Brakes are a 310mm front disc with a two-piston caliper and a 240mm rear with a single-pot caliper. Use them hard and they stop the bike quickly, if not too dramatically. There's plenty of subtle feel there to when you just want to lose a bit of speed without upsetting the suspension. ABS is standard, as demanded by law, and the final all-important link between the rider and the tarmac is a set of Metzeler Tourance Next rubber, 100/90-R19 at the front, 150/70-R17 at the back.

Weight is 178kg including a full tank of fuel, just undercutting the 181kfg Royal Enfield HNTR 350 but squarely beaten by the 170kg wet weight of the Triumph Speed 400.  

2025 Honda GB350S - Comfort & Economy

A low 800mm seat height, wide, flat bars and a long, roomy seat combine with relatively low-mounted pegs for a riding position that is spacious enough for most riders and didn't cause any aches or pains over 90 minutes. There’s nothing in the way of wind protection for higher speeds as standard but you can add a choice of screens – a low headlight cowl or a choice of two heights of standalone visors – to cut down on buffeting. Whether you need one is debatable. While the GB350S feels lively at lower speeds it struggles to keep up on motorways. Top speed is around 80mph but you work so hard to get the last 15mph that you soon end up avoiding motorways where possible. It's not a fault of the bike - just not what it is designed to do - like using your daughter's hair straighteners to make toast.

The other issue on long, faster journeys is vibration. Half an hour's fun down a national-speed limit A or B-road with the engine in the upper reaches of the rev range leaves fingertips tingling from the engine vibes. It's not the worst problem ever, but you do notice it.

Economy is a strong point of the low-revving engine. Our test bike averaged 96mpg in mixed usage - town, A-roads, B-roads, country lanes and a little bit of motorway. Combined with a 15-litre tank that’s a couple of litres larger than its main rivals, means a theoretical tank range of around 320 miles.

2025 Honda GB350S - Equipment

As you might imagine, a retro-styled, low-cost single-cylinder bike like the GB350S isn’t packed with all the bells and whistles when it comes to the equipment list.

You do get the basics, though, and the basics work very well. There's an LED headlight, a gear indicator set into the simple, analogue speedometer, plus a basic trip computer that gives fuel consumption readouts, estimated range to empty and an ‘ECO’ indicator to tell you if you’re sipping fuel as gently as you can.

The main controls - brakes, clutch, gearchange and throttle are all light and easy to use but with enough feel to help new riders learn how to control a motorcycle well. There's a centrestand, which makes checking tyres and keeping your chain adjusted and lubed so much easier.

There are a couple of more modern concessions including an emergency stop signal that flashes the hazard lights when you’re braking hard, and auto-cancelling indicators that turn off using a combination of front and rear wheel speed sensors to work out when you’ve completed a manoeuvre.

Except they don't always cancel if, for instance, you are indicating while filtering through traffic as opposed to turning. And at this point that 'ECO' light is one of the few things I'd change about the GB350S. It glows green and flashes on and off regularly. It also resembles the indicator warning light. So at times you are distracted, thinking you left the indicator on. And at other moments, when you thought you'd cancelled the indicator, but hadn't (because the indicator switch is a bit stiff), you ignore it, thinking it's the flipping 'ECO' light again. In the end I just taped over it.

The options list lets you add to the kit, with a ‘Style Pack’ that includes a single seat cowl, the low headlight cowl, side tank pads, fog lights and different bar ends. Or there’s a ‘Travel Pack’ with the taller 355mm screen, 24 litres of saddlebag space, and hand guards.

Other options include the decadence of heated grips and a USB charger, and any of the components of the packs can also be optioned separately.

2025 Honda GB350S - Rivals

The GB350S’s main competition is likely to come from the cheaper end of the Royal Enfield lineup. The £3899 HNTR 350 is the closest model in price, spirit and style, but the similarly-powered Classic 350 (£4539) and Bullet 350 (£4709) must also be considered competition. The larger Scram 411, at £4849, could be another competitor, and the company’s new Guerrilla 450 at £5050 offers a lot more performance and tech in a similar section of the market. Triumph’s liquid-cooled Speed 400, like the Guerrilla, easily outguns the Honda in the performance stakes and much also be considered a key rival despite costing more than £1000 more.

Royal Enfield HNTR 350 | Price: £3899

Read more

Power/Torque

20.2bhp / 19.9lb-ft

Weight

181kg

Triumph Speed 400 | Price: £5195

Read more

Power/Torque

39.5bhp / 27.7lb-ft

Weight

170kg

Royal Enfield Guerrilla 450 | Price: £5050

Read more

Power/Torque

39.5bhp / 29.5lb-ft

Weight

184kg

2025 Honda GB350S - Verdict

If the thing that gets you excited about biking is the joy of just being out there, the open road and your own 'bike lane' to discover, free from the hassles of traffic and being part of someone else's journey, then then go get a test ride on Honda's GB350S. It isn't a fast bike or a particularly exciting one. Think of it as smart, urban, transport with cool retro styling. All the urban performance you need plus great fuel economy and more involvement with the ride than a scooter. The GB350S is easy to use, but rewarding when you ride it well. It's motorcycling without the pressure and the 'how fast does it go?' b*llsh*t.

The only downside is the lack of speed on the motorway. Every now and then it's fine. Don't be too ambitious, stick in the inside lane and pick your moment to overtake the trucks. If your riding involves a lot of regular, busy motorway work, you'll be better off with a Triumph Speed 400.

Honda's GB350S could make a perfect bike for young riders with an A2 licence looking for something that looks cool and is affordable to buy and insure. The bike is built for gliding through town meaning it's brisk, but not quick, easy and friendly rather than a beast that needs taming. At 20.8bhp it is not powerful enough to be used for the A2 test meaning there's a danger some A2 riders might overlook it once qualified. For urban riders, that would be a mistake.

If you're new to riding and buying on finance, our suggestion would be to arrange the loan for the shortest possible time you can afford. The Honda's performance, while charming and easygoing may soon become limiting. All the easygoing riding, simple charm and relaxed zen moments will be overlooked by the devil on a new rider's shoulder curious to know just how much more fun another 25bhp could be.

If, however you're an older rider looking to downsize to something simple and fun, you'll just keeping on loving it for years.

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2025 Honda GB350S - Technical Specification

What is MCIA Secured?

MCIA Secured gives bike buyers the chance to see just how much work a manufacturer has put into making their new investment as resistant to theft as possible.

As we all know, the more security you use, the less chance there is of your bike being stolen. In fact, based on research by Bennetts, using a disc lock makes your machine three times less likely to be stolen, while heavy duty kit can make it less likely to be stolen than a car. For reviews of the best security products, click here.

MCIA Secured gives motorcycles a rating out of five stars (three stars for bikes of 125cc or less), based on the following being fitted to a new bike as standard:

• A steering lock that meets the UNECE 62 standard

• An ignition immobiliser system

• A vehicle marking system

• An alarm system

• A vehicle tracking system with subscription

The higher the star rating, the better the security, so always ask your dealer what rating your bike has and compare it to other machines on your shortlist.