The 310g Siuyiu W617 was by far the largest and heaviest light in our forthcoming six-way front light test. It was also the most powerful by a wide margin, flooding the road in front of me and appearing around twice as bright as the conventional-sized alternatives.
The W617 was tested alongside the Magicshine HORI 1300, Ravemen FR 1100 SE, Towild CL1200, CatEye AMPP 500 and Magicshine URBO FL. All six were ridden on the same unlit route and compared for beam performance, construction and mounting.
At £37, the Siuyiu’s proposition sounds implausibly generous. It claims a maximum output of 4,800 lumens, a 10,000mAh battery and several hours of runtime. We couldn’t verify the lumen figure, but the advantage over the other five lights was unmistakable on the road.
The W617 suits empty, unlit lanes
The W617 earns a narrow recommendation for riding on quiet country lanes where maximum forward illumination takes priority over weight and cockpit space. The broad flood exposes far more of the road ahead than the other affordable lights tested, and its £37 price is exceptional for that level of apparent output.
The weight and size make it cumbersome, and the maximum setting is also excessive when other road users are approaching. Riders wanting a compact light for mixed traffic have better options.
A broad beam with exceptional bulk
The W617 illuminated almost the entire area in front of the bike rather than concentrating its output into a narrow central spot. The flood reached approximately 100 metres along the test route, giving it considerably more reach and peripheral coverage than the five smaller lights.
Those five products looked like bicycle lights. The W617 felt closer to mounting a car headlamp across the bars. It was difficult to judge whether it achieved the claimed 4,800 lumens, but it appeared easily twice as bright as the conventional-sized models.
That output needs careful management, as the W617 could dazzle approaching road users at maximum power. The law (and specifically The Road Vehicles Lighting Regulations 1989) points out that vehicle lights, including bicycle lights, must not cause “cause undue dazzle or discomfort to other persons using the road.”. Its brightest setting therefore makes most sense on empty stretches.
The top-mounted display is one of the W617’s most useful features. At maximum output it showed an estimated 4.3 hours remaining, expressed as time rather than a basic battery bar. Siuyiu claims a runtime of between seven and 16 hours and a nine-hour full charging time.
Build quality
Despite the low price, the light felt solid and better finished than expected. The housing combines aluminium and plastic, with a broad face accommodating the LED array. A button cycles between floodlight, spotlight and full-beam modes, and the light has USB-C charging.
Compared to the other lights on test, the packaging was essentially a brown cardboard box. I guess it’s reassuring to know that your money has gone on the light and not on graphic design and fancy packaging.
The mounting design uses two separate handlebar attachments with thumb screws. Once those are fitted, the light slides onto a rail beneath its housing. The arrangement looked ungainly before installation, but it remained surprisingly stable during a brief mounted test. I’d be less confident taking on longer rides on rough terrain.
Verdict
The W617 is an amazing light for the price, but it’s hard to see that many applications. I thought it would fit squarely in the too-good-to-be-true category but was blown away by the build and power. If your only priority is turning the road in front of you from night into day, then this is the light for you.
Buy it for quiet, unlit country lanes if maximum light outweighs its 310g weight and large handlebar footprint. Riders using busier roads should choose a more controlled beam, while trail riders need something more secure before relying on it over rough ground.
