Suzuki DR-Z4SM Review – The new Suzuki Supermoto

6 months ago 134

ARTICLE AD BOX

Suzuki DR-Z4SM Review

Suzuki has given its venerable DR-Z400SM a proper revamp (and a new name) for 2025. That means that is time to go for many, many skids on the new Suzuki DR-Z4SM.

There are very few motorcycles that make me laugh quite as much as a supermoto. This most underrated form of riding has been forgotten by all but two mainstream manufacturers. Thank God they have the courage to put a factory-built 17-inch dirt bike on the street for us to buy, rather than requiring us to convert a dirt bike ourselves and suffer the pitfalls of our own shoddy workmanship.

Suzuki has been in the supermoto game for an impressive 20 years, with the DR-Z400SM first introduced in 2005. In that time, the model has seen gradual updates, but it hasn’t received a complete makeover until 2025, as it moves lockstep with the DR-Z4S that’s coming our way in December.

To make a (very) long story a little shorter, the $14,990 ride-away 2025 4SM shares about 90 per cent of the upgrades the 4S brings to the market. Suzuki is claiming 37.5 hp at 8000 rpm and 38 Nm at 6500 rpm from the 398 cc single-cylinder motor, which is slightly less than the outgoing model that wasn’t Euro5-compliant.

The engine receives a new intake, cylinder head, cam profile, titanium intake valves, sodium‑filled exhaust valves, dual iridium spark plugs, a new piston, crankcase that no longer needs the kickstart bosses and hole, and it’s all fed through a 42 mm throttle body with the mixture sparking off a 10‑hole injector.

Increased low-down torque was the aim of the game with the new 4SM, making it a more rideable proposition for general street riding and traffic light GPs. Interestingly, Suzuki claims the new motor has a 20 per cent reduction in mechanical losses at 8000 rpm, which shouldn’t be too hard to achieve, given that the previous motor can trace its heritage back to the last century.

Diehard fans of the DR-Z range have been howling for a sixth gear for a long time, but Suzuki decided against fitting one to this and the 4S dual-sport machine, citing weight and manufacturing cost concerns.

As such, the engine’s go is transmitted to the tyre using the same five-speed transmission as before, and this proved to be one of the bike’s major flaws when we conducted freeway riding or any riding north of 90 km/h, for that matter, as the revs felt too high and a lack of top-end acceleration hurt the SM’s potential. Oh, we can’t even tell you what revs we were doing at 90 km/h because there’s no rev counter on the 4SM’s dash

Suzuki has tried to reduce the impact of not having a sixth gear by giving the 4SM a smaller rear sprocket for taller gearing (41 teeth compared to the 4S’s 43 teeth, although both use the same 15 tooth front sprocket), but the lack of a sixth gear is still a glaring omission from Suzuki’s engineers.

As for the clutch, it is now a slip and assist type that uses Suzuki’s Clutch Assist System (SCAS) for a light lever pull. Performance junkies will note there’s no quickshifter, nor the option of upgrading to one in Suzuki’s aftermarket catalogue.

Regardless of the missing quickshifter, the 4SM still receives a significant upgrade in the electronics department with the installation of the Suzuki Intelligent Ride System (S.I.R.S.). This includes the Suzuki Drive Mode Selector (SDMS) and the Suzuki Traction Control System (STCS), which features the same G (Gravel) mode as on the 4S but with a different level of slip (i.e more electronic intervention). And, like the orange arch-rivals from Austria, the 4S now has ABS that can be turned off on the rear, but being a street model, it is always engaged on the front wheel.

The bones of the 4SM have also been drastically altered. Gone is the steel tube single cradle frame; in its place sits an all-new, twin-spar aluminium design with the engine’s oil now in the frame.

Suzuki claims a 9.3 per cent increase in torsional rigidity with the new chassis, featuring suspension now inverted with 46 mm KYB forks up front (adjustable for compression and rebound) and a fully adjustable KYB monoshock out back. Wheel travel has gone up 20 mm up front and 18 mm at the rear, respectively.

Braking hasn’t changed in the Nissin twin-piston caliper gripping a 310 mm disc up front and a single-piston caliper stopping a 240 mm rotor at the rear. And although the wheels haven’t changed, Dunlop has fitted the 4SM with their Sportmax Q5A rubber.

Ride impression

A supermoto between traffic lights is one of motorcycling’s great joys, and here the 4SM delivers beautifully. The 4SM is perfectly designed as an inner-city zip-around bike, one that will happily carve your local twisty roads with the best of them. If you stick to those areas, the 4SM is hard to fault.

Baseline suspension settings are extremely soft, and if you want to get out there for a rip, you’ll definitely want to jack up the rear preload and stiffen the fork. The good news is that the 4SM really responds to a few clicks on the clickers here and there, which bodes well for the overall quality of the KYB suspenders.

The 4SM is very light on its feet thanks to the surprisingly competent Dunlop Sportmax Q5A. Compared to the Michelin units found on the KTM 390 SMC-R, the Dunlops have a more tactile feel thanks to being slightly softer in their carcass. All this means it’s easier to feel what the Suzuki is doing underneath you.

The chassis is light and agile, allowing you to pick and choose your line with the same ease as a minimoto, not a supermoto. This is the appeal of a bike such as this: it’s incredibly easy to use and use well. It won’t scare you and offers enough performance that riders of almost any skill level can enjoy.

One could argue that you don’t need adjustable riding modes on the 4SM, and that person would be correct. They are entirely superfluous for the needs of a sub-40 hp motorcycle, but having adjustable traction control and switchable ABS is a good feature.

The 399 cc motor’s increased low-down torque is noticeable on the street. Cruising from stop sign to stop sign is a little less urgent than on the previous iteration, so it gives you a more relaxing ride in this instance.

However, a lack of a sixth gear is a significant problem given how buzzy the motor becomes at freeway speeds. No amount of gearing change is going to make up for this, and given KTM has a sixth gear on their 390 SMC-R, Suzuki will really want to rectify this in the near future.

The lack of a sixth gear also hurts the motor on the racetrack as it begins to run out of steam a little too early for my liking. Overall, the gear ratios themselves are nicely spaced, there’s just not enough of them…

Another area of concern is the discomfort of that seat. Yes, I know it’s a dirtbike seat and all, but my goodness, it is seriously painful after an hour on board. This further leads the bike towards short, sharp journeys where there are a few wheelies and back-ins to be had, and for that, few match the 4SM for outright laughs.

However, the big white elephant in the room is, you guessed it, the price. At $14,990 ride-away, that is a massive difference over its nearest rival in the $10,695 ride-away KTM 390 SMC-R, a machine that has a lot more features, including a TFT dash that has phone connectivity and can therefore turn-by-turn navigation, a 12v/USB-C socket (this can be added in Suzuki’s aftermarket catalogue), and… a sixth gear.

I know we’re not directly comparing the two in this article, but potential buyers certainly will be, so I suppose a head-to-head test is in order.

What the Suzuki has on its side is its rock-solid reputation for build quality, with the entire bike manufactured in Japan at the Hamamatsu factory. These are similar to Honda’s XR in that you can’t kill them with a brick, and that is a legacy built over decades.

I personally feel the 4SM is about $2500 too much, given what you get, but I am not involved in any of Suzuki’s marketing and pricing. However, there’s a good chance this 4SM will be the one left standing in another 20 years’ time thanks to that famous reliability.

Regardless, it is excellent to see Suzuki has kept the supermoto faith all these years. Time to go for another skid…

Suzuki DR-Z4SM Specifications

2025 Suzuki DR-Z4SM Specifications
Engine type	Four-stroke, single-cylinder, liquid-cooled, DOHC
Bore x stroke	90 x 62.6 mm
Engine displacement	398 cc
Peak power	38 PS (28 kW) @ 8000 rpm
Peak torque	37 Nm @ 6500 rpm
Compression ratio	11.1:1
Fuel system	Fuel injection, RbW, STCS, SDMS (TC/Ride Modes)
Starter system	Electric
Lubrication system	Dry sump
Transmission	Five-speed constant mesh
Suspension Front	KYB USD fork, compression, rebound adjustable, 260 mm travel
Suspension Rear	Link type, KYB monoshock, fully adjustable, 277 mm travel
Rake/trail	26.5°/95 mm
Brake Front	310 mm disc brake, axial mount caliper, ABS
Brake Rear	240 mm disc brake, axial mount caliper, ABS
Tyres	120/70R-17M/C58H, 140/70R-17M/C66H tubed
Wheels	17/17 inch
Overall length	2195 mm
Overall width	885 mm
Overall height	1190 mm
Wheel base	1465 mm
Ground clearance	260 mm
Seat height	890 mm
Kerb mass	154 kg
Ignition system	Electronic ignition
Fuel tank capacity	8.7 L
Oil capacity (overhaul)	1.9 L