The Knog PWR Rider Duo is designed explicitly as a helmet light and features a 450-lumen maximum-power front light and 12-lumen detachable rear light.
The 2,200mAh battery can also be used as a power bank to charge external devices and is housed in a sleek aluminium tube.
The detachable rear light has a plastic cover that helps keep the light watertight and is rated to IP66 (sealed against dust and powerful jets of water).
The battery is charged through a micro-USB port. There are four red LEDs on the top of the light’s body that serve as a battery-charge indicator.
The light features six modes claimed to last between two hours at full power (450 lumens) and 50 hours in Eco Flash mode (50 lumens). You can toggle through these with a small button on the underside of the casing.
A neat feature of this light is the ability to customise the modes through Knog’s Modemaker app, so you can add or remove modes, choose between set flash patterns and select the brightness of standard modes.
The light weighed in at 151g on my scales.
The mount comprises a GoPro-style connector on top of two flat plastic plates bolted together through a helmet vent.
Knog PWR Rider Duo helmet light performance
Attaching the mount to your helmet requires a bit of finesse because you need to be careful with a 4mm Allen key on the plastic bolt that fastens the two parts together. These clamp together through a helmet vent.
I would have liked to have seen some padding on the mounts to offer a little extra protection and a less slippery surface. Knog also uses a tiny bolt to attach the light to the mount, which is a bit of a fiddle.
That said, once the light was installed, it remained in place during testing and didn’t rattle or move around.
With the light mounted, toggling through its modes was easy, even though there’s only a small button on the underside. The button was easy to find with gloves on and has a definitive click, making counting mode changes much more straightforward.
If you don’t want to toggle through all six modes, you can customise them through Knog’s Modemaker app. However, I didn’t feel this was necessary for testing, because toggling through the modes takes just a few clicks.
Nevertheless, it’s an intelligent feature, and if it were my only light, I’d probably limit it to two constant modes – full-power and half-power.
The PWR Rider Duo will also remember which mode it’s in when you turn it off. The battery indicator is simple but helpful for keeping track of remaining charge.
The 450-lumen Knog does an impressive job considering its low power. It’s possible to ride with this light by itself, but I certainly wouldn’t recommend it.
Its white light has a decent spread from its elliptical beam pattern, which enables you to pick out the trail edges and helps keeps you on track. This white light doesn’t tire the eyes or have any distinguishable hotspots, but that’s to be expected from a unit with an output of only 450 lumens.
The throw from its beam pattern is okay but not class-leading, so vision down the trail isn’t great. It doesn’t illuminate trail features in the distance that well.
This is compounded by the lack of a strong central focus point. The beam is diffused evenly, meaning the Knog isn’t great at highlighting specific trail features, but instead gives a broader but less bright view of the trail ahead.
The main issue is that when riding with a brighter handlebar-mounted light (2,000 lumens), the Knog isn’t powerful enough to punch through and add meaningful additional lumens.
When looking at the exit of turns, it provides more of a glow than a focused beam that enables you to see where you’re going and highlight what’s coming next.
At full power, the light ran for two hours, seven minutes, which is pretty impressive. This is the benefit of having fewer lumens – power consumption is lower.
Knog PWR Rider Duo helmet light bottom line
The PWR Rider Duo packs a decent punch for its 450 lumens. The diffused white beam has a good spread that helps pick up the trail’s edge and a moderate throw to help you see into the distance.
The additional red rear-light end cap is helpful for road sections of a ride and can be removed easily when needed.
The diffused beam pattern lacks a bright spot in the centre to highlight trail features, and the low lumen count makes it hard to ride at speed.
The small helmet mount lacks padding and needs a tool to fasten it enough, but it was stable when in use.
How we tested
We put six helmet-compatible lights to the test. With prices ranging from £65 to £265, there should be something for everyone’s budget.
The lights chosen here have an output of 450 lumens up to 2,100 lumens. That covers everything from occasional use or as a backup light, to full-on, high-speed riding.
We tested how each light performs riding back-to-back runs on the same trails, comparing beam pattern, LED colour, ease of operation and, most importantly, light projection.
We also timed them all on maximum power to find out just how long the batteries last, and whether they live up to the brands’ claims.
While many of these lights can also be used as handlebar-mounted units, for this test, they were specifically reviewed for use as helmet lights for off-road night riding.
Head to BikeRadar’s round-up of the best helmet lights for our pick of the bunch.
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