Moon Helix Pro-W Front Light

The Moon Helix Pro-W is a relatively sophisticated yet user-friendly be-seen-by or secondary light, with enough bite for town work and much better peripheral punch than the slab-sided profile might suggest. There are several cheaper compact lights offering more power if you weren't needing the Moon's intelligent, tuneable technology, though.

For more options, check out our guide to the best bike lights.

The Helix Pro-W is very well made. Its CNC machined aluminium casing is both solid and serves as a heat sink, so the COB (Chip on Board) diodes stand the best chance of living long and productive lives.

The lens continues this solid, efficient theme, and everything seems well sealed from the elements. It meets IPX7, which means it will survive up to 30 minutes full-on immersion in metre deep water. There's been plenty of opportunity for calling its bluff in these parts, thanks to Storm Ciaran, but I wasn't surprised to find it passed with flying colours, mounted on my rough stuff tourer's fork legs for 200 miles.

Modes & settings

There are five factory presets, as well as user-programmable modes, plus two 'Intelligent Operation' settings.

The brightest stock mode is the 250-lumen Day Flash, with two more flashing – Steady Flash (10+80 lumens) and Flash 1 (50 lumens) – plus two steady modes, Mode 1 (130 lumens) and Mode 2 (10 lumens). Run-times are cited as between 2hrs 15mins (Mode 1) and 27 hours (Steady Flash).

The user-programmable modes come under the Variable Lumen System (VLS) setting, which allows you to set output to taste or need. I first met this on the Meteor Vortex Pro back in 2020. Basically, you press the switch until you reach the desired mode and output, hold until the light flashes, and you're set. To reset, turn the light off and hold the switch for 10 seconds.

On top of this is what Moon calls 'Intelligent Operation', which has two functions – it measures ambient light and adjusts output accordingly, or works as a standby, putting the light to sleep when it senses inactivity, and coming to life again when it notes movement. Stationary for 60 seconds, the light will power down and then perk up again when movement is detected. After an hour, it'll shut down completely – a thoughtful feature for those times when you've rushed home, popped the bike away and forgotten about it in your rush to the shower.

We also have an Auto Safe Mode (ASM). Essentially, this is an automatic emergency kick-down when battery reserves tumble, giving approximately 45 minutes to limp home on. It will also protect the battery and cannot be overridden.

It also has a memory mode function, so will switch back on in the last mode used.

Switch

The switch is an obvious, user-friendly unit, even in the dark when you're wearing winter-weight, full-finger gloves.

I'm pleased to report it requires a definite, half-second press, so accidental power-ups are unlikely – come to think of it, I've never found a Moon light switching itself on in a pocket or the bottom of a pannier. However, in common with the Meteor Vortex Pro you can go belt' n' braces and lock it. To do this, turn the light off and press the switch for six seconds and the light will flash twice; repeat to unlock.

Mount

Moon has gone for a Garmin type mount, and the Helix Pro W fits and releases very reliably. Two straps are supplied, one for 25.4-26mm or thereabouts, the other for 31.8mm tubing. It played nicely with some hybrid drop bar designs, 1in head tubes and older steel fork blades without slippage. Should you lose one, I'm pleased to report some generic o-rings also make reliable substitutes.

While we're on the subject of mounting, Moon recommends positioning the light away from wireless computers. I've kept it a subtle distance from head units and sensors but not neurotically so, and no wacky readouts thus far.

Performance

I've used the Helix Pro-W primarily as a dynamo companion on pre-dawn and evening rides, and output and performance have been consistently good across the board, town and backwaters alike.

During the daytime, the Day Flash is very extrovert and reassuringly obvious, even in relatively strong winter sunlight. Along country roads, oncoming vehicles seemed to register it at around 100 metres, and casual chat with other riders suggested 150 on duller days. Predictably, this dipped a little through town and, anecdotally, in these contexts it seemed more effective when positioned horizontally.

Around dusk and beyond, used as my only form of lighting, the 130-lumen steady had enough presence for being seen through the suburbs at full pelt, although I found going the VLS route – 250 steady and 10-lumen flashing – was best, especially when entering the flow of traffic, exiting roundabouts and so on.

The lens projects a decent arc of light, although isn't intended to be navigated by – switching off my main, high-power systems confirmed this beyond any doubt – but I was reassured by the arc of light keeping me visible.

Satisfied with this, I switched to the Intelligent mode, which measures ambient light and adjusts output accordingly. Sensored lights have become a lot more sensitive – in the right way – and the light seemed to make accurate choices and with minimal lag, depending on conditions: brighter when I was entering an underpass, staircasing downward when I re-emerged. Testing aside, I've defaulted to this, which should tell you something.

Charging

The lithium polymer cell charges via a USB-C cable, and did so in 2.5 hours, less at the mains.

Run-times for the factory preset modes have been within a few minutes of those cited, and the Auto Safe Mode has done its thing reliably, giving the full 45 minutes before finally powering down.

It's best not to deplete the battery too often since this can prematurely shorten the lifespan of lithium-ion and lithium polymer batteries. Moon also recommends charging to 50% if you're going to put the light away for a while.

Value

For its tuneability and effective sensors, the Helix Pro W's price of £49.99 is pretty good – an Exposure light with Reflex technology that automatically adjusts output can cost another £200+ on top!

However, if you can do without the same intelligent functionality there are several options out there producing over 400 lumens for less money.

Steve was generally impressed with Oxford's UltraTorch Headlight CL500, for example, which comes in at £37.99 and pumps out 500 lumens, though he found the mount a little fiddly and its IPX4 weatherproofing is a few steps down from the Moon.

Cheaper still at £34.99 is the Giant Recon HL350, which impressed Lara with its ease of use and run-times.

Or, for the same money as the Moon, Knog's Plug Twinpack includes both a front light with 250 lumens and a 10-lumen rear.

Conclusion

As above, there are several traditional compact lights offering greater output for less, so unless you were set on the intelligent tech I'd steer you towards one of these if you were seeking a light for commuting and training. In my view, the Helix Pro W is best seen as a frugal yet extrovert secondary or contingency light, either for extended summer playtimes on the best bike, or companion to more powerful rechargeable and dynamo setups.

Verdict

Not the cheapest for the output, but solidly made, with some excellent settings and tuneability