Ridden: New 2017 Suzuki GSX-S125 featured image

Ridden: New 2017 Suzuki GSX-S125

26 Sep 2017
Suzuki's new generation of 125s boasts this little ball of naked wonder...

Suzuki’s new GSX-S125 is a little cracker.

It’s no scorcher (what do you expect when it’s packing 14.6bhp?), but it delivers a great fun ride that will help a new generation of motorcyclists learn the art of riding properly.

We joined the European launch of the learner-legal naked four-stroke on the roads around Silverstone circuit and had a ball. There’s something about keeping a little 125 simmering that will always appeal to us riders, whether we’re fresh-faced L-platers or grizzle-chopped vets with a cynical streak as wide as Greenland.

‘The high-revving engine demands stirring’

The GSX-S derives from the 150cc model manufactured and sold in huge numbers in bike-crazy Indonesia and is very similar to the GSX-R125 that was presented at the same European launch.

The GSX-S and GSX-R share the 124.4cc engine, which makes its peak power of 14.6bhp at 10,000rpm. The frame and running gear are also shared across the two machines, and the GSX-S is the naked version with straight bars and a more upright riding position.

Damned good fun it is, too. That high-revving engine demands plenty of stirring to keep it whipping along, but that’s the main appeal of 125s like this. Those of us with more experience get to wrestle out every milligram of performance, which, on the road, is asking for trouble when you’ve much more than 500cc to play with.

New riders, who will clearly be the biggest audience for the new GSX-S125, will inevitably learn some important riding lessons. There’s no better incentive for choosing the right line into and through a corner than knowing you’ll lose hard-earned momentum if you get it wrong.

‘It’s easy-going for those taking their baby steps into motorcycling’

The GSX-S’s DOHC motor is soft and friendly at low revs, easy-going for those taking their baby steps into motorcycling. The clutch is light and the gearshift is easily manageable. Neat touches like a one-press starter button (no need to hold it in until the engine fires) make life even easier for first-timers, too.

The engine starts to do its real work at around 7000rpm, but it’s at 8000rpm that it gets properly moving as it reaches a peak torque of 8.48 lb-ft (every 0.01 lb-ft counts at this level, you know).

From here to 10,000rpm is the sweet zone, though the GSX-S will rev on to 11,500rpm before reaching the redline. It’s only here that the brilliant LCD instruments illuminate a small light requesting we shift up a gear, though experience suggests it’s best to knock it up at 10k instead (the rider can programme their own light-up point).

‘It turns neatly and remains composed even when carrying a 95kg rider’

This kind of high-revs, maximum-momentum riding demands a capable chassis – and the little Suzuki definitely delivers.

On paper the spec looks lower than some competitors, with conventional forks where some rivals boast stiffer and flashier upside-downers. The wheels and tyres are also narrow – the 90-section front tyre is 10mm slimmer than Yamaha’s competing MT125 and 20mm down on KTM’s equivalent 125 Duke. The Suzuki’s 130-section rear matches Yamaha but is again 20mm down on the KTM’s 150-section back tyre.

But this isn’t the slightest issue on the road, where the GSX-S copes well, turning neatly and remaining composed when carrying a 95kg rider on its back. That’s heavier than the average rider who will be throwing a leg over a bike like this.

The benefits of wider tyres are often over-rated, and the slimmer offerings on the Suzuki aid turn-in speed. They are also contribute greatly to Suzuki’s quest to keep weight down on the GSX-S. 

The claimed kerb weight of 133kg is the lowest in class – 7kg lighter than the Yamaha and at least 4kg lighter than the KTM, which claims a dry weight of 137kg (its fluids will add extra kilos). Aprilia are also playing in this class with the Tuono 125, but the Italian manufacturer is shy about revealing its bike’s weight.

Suzuki makes a big deal of its effort to keep weight down, saying that explains the use of conventional forks rather than stiffer, heavier upside-downers that also demand other parts are made stiffer (hence heavier) to cope.

The plastics, however minimal they are on this GSX-S125, are also made using a resin-moulding technique perfected on the GSX-R1000 to shave off crucial extra weight. Suzuki also claim the frame alone is 3kg lighter than competitor frames.

‘I had a great time on the GSX-S – it felt like a baby Triumph Street Triple’

On the road, the GSX-S feels light, small and short. There’s more room for bigger riders than on its GSX-R sibling, thanks to the upright riding position, but it’s still short in both regards. The 1300mm wheelbase is at least 50mm less than either the Yamaha or KTM competition and the 785mm seat height is much more friendly to shorter riders than either (the Yam’s perch is 810mm off the floor and the KTM’s 830mm).

It’s dinky without being tiny – giving a hint of the appeal of tiddlers like Honda’s MSX125 without anything like the impracticality. I’m 5ft 10in tall, weigh too much (95kg) and I had a great time on the GSX-S. It felt like a baby Triumph Street Triple – and I love Triumph Street Triples.

Where I expected the GSX-S to collapse in protest when I lowered myself onto its narrow back, its non-adjustable suspension supported me well. The minor handling issues that emerged when testing the similar GSX-R125 on track didn’t present themselves in the more realistic environment of the road, which is where both the 125cc bikes will be ridden.

Forks dive under heavy braking, but it’s more helpful than hurtful, putting weight over the front tyre to increase grip. Those brakes do a good job of hauling up the combined 228kg (rider and bike).

The Bosch ABS on the front never interferes in general riding and even a deliberately provocative handful of front brake doesn’t bring it into play, suggesting it will leave well alone unless it’s genuinely needed.

The ABS on the back kicks in much earlier and renders the rear stopper a little weedy, but that’s often the case on bikes of a far higher spec than the GSX-S.

My only complaint after a morning’s riding was that small proportions around the handlebars made two-fingered braking impossible. The brake lever bumped into my third and fourth fingers before reaching the biting point, meaning I had to use all four fingers. Adding a span-adjustable lever would sort the issue out.

‘Even when thrashed a tank’ll last ages’

So all of this leaves us to deal with the practicalities. Things like these are vital on a 125, often run on a low budget.

The Suzuki is cheaper to buy than its rivals, sitting at £3699 in the launch colours of white/red and black/red, or £3799 for the striking replica paintscheme from Suzuki’s MotoGP team.

That compares favourably with the £4099 KTM 125 Duke and £4299 Yamaha MT125. The Suzuki comes in almost a grand less than Aprilia’s £4600 Tuono 125.

Fuel economy on the GSX-S is good, too. Our test involved B-road thrashing and very little time for the Suzuki to kick back and chill, but it still recorded 82mpg. Expect that to improve a little in less extreme use and you’re looking at impressive frugality. Even at our ‘thrashy’ rate of consumption the 11-litre tank (2.9 imp gallons) will last 237.8 miles between fill-ups.

If anyone wants to ride more than 237 miles in one go on such a small bike then they’ll need more than their head examining.

The fuel economy figure comes from the delightful instrument cluster, which maintains Suzuki’s fine recent form on this score. It’s the same type as used on the GSX-S1000 and SV650, using a very clear and simple LCD screen to show speed, revs, gear position, fuel level, average fuel economy and two trip readouts.

It is very good and stands comparison with bigger machines, only lacking a complicated (and doubtless expensive) fuel range countdown. But these are the sort of fripperies that appeal to older riders, not the whippersnappers likely to be tempted by a GSX-S125.

A worthy addition to the GSX-S comes in the shape of an anti-tamper ignition barrel, adapted from Suzuki’s scooters. A small thumb lever operates a shield that slides over the keyhole to protect from unwelcome screwdriver butchery. When the rider returns to the bike they insert a code-matched magnet that lives on the side of the ignition key and it releases the shield to reveal the keyhole.

Plenty of these bikes will be the rider’s only means of transport and will spent a lot of their time outside, rather than cosseted in a dry, locked garage. Simple anti-theft measures like this one from Suzuki are to be applauded.

‘The Suzuki GSX-S125 is a diamond of a bike’

The world of 125s has moved on a hell of a lot in recent years. Yes, the era of the two-stroke has gone (long gone). But the smoke haze has cleared to reveal a cleaner, neater, sharper and funkier generation of learner machines that are credible bikes in their own right.

All in, the Suzuki GSX-S125 is a diamond of a bike. Compact, light, fun and cheaper than its rivals. It carries the ethos of Suzuki’s bigger bikes well, delivering good results without charging the earth.

Whether you’re looking for your first bike or something to whizz around town and country for cheap thrills then the GSX-S125 is well worth a serious look.


£3699-£3799 (price correct August 2017)

Engine 124.4cc single-cylinder four-stroke, liquid-cooled DOHC
Bore x stroke 62.0mm x 41.2mm
Compression ratio 11.0:1
Power (claimed) 14.6bhp @ 10,000rpm
Torque 8.48 lb-ft at 8000rpm
Fuel system Fuel injection
Wheelbase 1300mm
Front suspension Telescopic, coil spring, oil damped
Rear suspension Link type, coil spring, oil damped
Rake/trail 25.5°/93.3mm
Tyres 90/80-17 (front), 130/70-17 (rear)
Seat height 785mm
Kerb weight 133kg
Fuel capacity 11 litres
Fuel economy 83mpg (tested)
Further info https://bikes.suzuki.co.uk/bikes/