2026-on QJMotor SRK421RR review | Sports screamer for less

QJMotor SRK421RR expert review

3 out of 5 (3/5)

Back in the late 1990s and early 2000s, Japanese ‘grey import’ bikes were the cheapest way for young riders to access proper sportsbike thrills. Near perfect mini-replicas of their bigger-capacity siblings, the likes of the NC30, NC35, ZXR400, GSX-R400 and FZR400 sold like hotcakes thanks to their exotic nature and rev-happy motors.

But then something changed, and for the best part of twenty years, their kind vanished from showrooms, replaced in recent times by lower-powered, budget-conscious parallel twins or singles aimed mainly at the Asian market.

Recently Kawasaki reintroduced the screaming inline-four in the shape of the Ninja ZX-4RR and now it has a rival from China: the equally rev-hungry QJMotor SRK421RR.

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Is the QJMotor SRK421RR right for you?

Reasons to buy:
+ Thrilling engine performance despite relatively small capacity
+ Firm sporty ride with front and rear suspension adjustment for finer tweaks
+ Easily the most affordable new-gen inline-four cylinder sportsbike

Reasons to avoid:
– Looks are far from subtle
– Long-term durability has yet to be proven
– Needs 8000+rpm to get the best from it

Feel the frenzy…

When you see a rev counter that ends at 16,000rpm, you know there is a fair chance you will have to rev an engine to get the best from it, and sure enough, the SRK421RR does thrive on being hammered.

Initially you think this might not be the case, as after a bit of clutch-slipping to get you rolling it pulls surprisingly well at its very bottom end, but at 4000rpm the motor seems to become strangled, and until 8000rpm it’s more than a bit wheezy. Then the fun starts.

Keep the digital rev counter above 8000rpm and the inline-four starts to sing, wailing wonderfully from its airbox and gathering pace with enthusiasm until it hits the rev limiter.

Considering it is only 421cc, this rev-happy nature makes the QJMotor a surprisingly brisk machine, and one that, should you keep up with its crank’s demand to be kept spinning, can certainly get a shift on.

Intoxicating to ride and genuinely entertaining, it reminds you of the fun to be had hammering the hell out of a motor and gearbox with manual blips between every downshift and perfectly timed clutchless upshifts (there is no quickshifter) rapidly becoming second nature.

Obviously you can ride it more sedately, but it’s nowhere near as fun…

Commitment is required

Thankfully the SRK comes armed with a chassis that is able to keep up with the motor’s demands – although it too also requires a fairly high level of rider commitment.

Boasting Marzocchi suspension and Brembo brakes, the SRK feels like a mini sportsbike, and its ride quality is fairly harsh and unforgiving as a result.

Although the riding position isn’t too extreme, bumps in the road jar your wrists and back as the suspension isn’t very compliant, and the CST Ride Migra S3N tyres take a bit of warming up to get the best from them.

However, if you put in the effort, the whole package gels together, and the SRK responds like a proper mini sportsbike. Kneedown is certainly on the cards, and you can attack bends with real enthusiasm (fairly…) safe in the knowledge the SRK’s chassis is up to the task.

Safety is also covered

Generally smaller bikes don’t feel like they need traction control, but it is nice to see this feature alongside ABS on the QJMotor. Developed by Bosch, the combination of Brembo brakes and ABS gives the lightweight SRK an impressive amount of stopping power, and despite being a bit abrupt when it cuts in, it is better to have TC than not.

How does it compare to the Ninja?

If you are talking pure performance, the Kawasaki Ninja ZX-4RR comes with a smaller 399cc capacity motor which makes an almost identical 75.9bhp with 28.8ftlb of torque to the SRK.

Chassis-wise, the Ninja also features a steel frame with inverted forks, but only its shock is fully adjustable; the forks can only have their preload altered, whereas the QJMotor has fully adjustable forks and rebound and preload adjustability on its Marzocchi suspension.

Both bikes have radial front callipers, but the QJMotor features Brembo units, whereas the Ninja runs Kawasaki-branded items, and both bikes run 120/70 front and 160/60 rear 17in wheels.

Tech-wise, they are identical with ABS, traction control, variable power modes and connectivity as standard fitment, but the SRK lacks a quickshifter (it could be an option soon).

But the crunch point is price – the Ninja ZX-4RR costs £8913 where the SRK421RR is £5599…

How long can it last?

Considering the mechanical abuse that the SRK421RR is destined to have to endure throughout its lifespan, you are left slightly wondering just how long it can withstand it.

The gearbox gets an absolute hammering, and our bike seemed to develop a bit of a drivetrain clunk, which could just be down to a slightly slack chain.

The SRK comes with a two-year warranty as standard, which is reassuring, and you can always buy it on PCP and hand it back after the finance package expires…

A range of options

QJMotor’s models are imported into the UK by MotoGB and have a total of 42 dealerships, 35 of which stock the full model range, with seven just dealing with small-capacity bikes.

They first arrived in 2025 with a range of 16 models, which has now been expanded to 26.

The bikes include 50cc and 125cc scooters, 125cc motorcycles, a range of middleweight parallel-twin and V-twin adventure bikes, a 561cc V4 cruiser, a 421cc inline-four sportsbike, 904cc parallel-twin adventure and naked bikes, 778cc inline-four naked and sportsbike and a range-topping 921cc inline-four sportsbike and naked bike.

MCN Verdict

Chinese bikes need to have a unique selling point to entice buyers to give them a chance, which is exactly what the SRK421RR has.

Costing a massive £3314 less than the ZX-4RR, it allows QJMotor to capitalise on the fact younger riders might not place as much emphasis on ‘known brands’ as older ones, so they will be prepared to give them a shot (especially with the WSS and Moto2 and Moto3 connections) and buy on spec, looks and price rather than focus on the company behind the bike.

On this score, the SRK421RR is extremely good value for money, and as well as looking fantastic, it rides well – as long as you are prepared to give it some commitment and are happy to rev the bejesus out of the motor…