Moon Helix Sense 450lm

The Moon Helix Sense is a sleek and innovative rear light that offers excellent brightness for day and night riding, with good side visibility. It is packed with super-smart features – including a braking sensor and park function that will turn lights off when you've stopped moving for a while. And it comes with an array of settings that cover everything from daytime rides and urban commutes, to long night rides, where its impressive runtime really comes into play.

For more options, check out our guide to the best rear bike lights, and if you need a new front light, we have a buyer's guide for those for those too.

When the Moon Helix Sense 450 arrives, you can crack open the box to find the light along with a seat post mount, two rubber bands of different lengths and a pair of rubber bungs that you can match to the size and angle of your seatpost.

There are two other mounting options – one a sliding 'belt clip' that will attach to a rucksack or clothing, and a 'saddle rail bracket' that requires a pair of zip ties to attach securely.

The build quality feels very good indeed. The light has a CNC aluminium heat sink casing and an IPX7 waterproof rating, which means it will cope with anything the weather throws at it. The USB-C charging port is located behind a rubber cap that locks securely into place. Plug in the cable and the manufacturer claims a two hours and 30 minute recharge time from empty, which tallies with my experience.

When you are ready to set off, simply give the light a three-quarter turn to lock into your chosen mount. You'll be familiar with this from most computer mounting systems and it delivers a secure fastening that will stay firmly in place, no matter how bumpy the ride.

Feature packed

There's one central switch located at the top of the light. Give it a single, swift click to switch it on. You can then give it a double click to switch between flashing and constant modes, and then a subsequent single click to rotate between three flashing and two constant modes.

You can also select the lumen output you want for your particular ride. You do this by choosing your desired mode and then holding the button to turn the lumen level up and then down. Simply release the button when you've got the light setting you want.

This is when you can really marvel at the output that is on offer from the three LED boards inside this rear light. In flashing modes the central board can operate separately from the two side boards, which opens up an array of day-time disco options.

As if that single button didn't have enough on its plate... you can also use it to access the 'sense mode' that alerts traffic when you are braking. You do this by powering off and holding for three seconds until you get a single flash of a green light at the base of the light.

The little light indicator also flashes blue. A slow blue flash means that the battery is low and it's time to recharge. A quicker flashing blue means that it has entered safe mode, and you have one hour 30 minutes of run time to get yourself home.

Thankfully the light is also exceptionally smart and it can take control of some of the features without having to remember another combination of button clicks. Its built-in smart light sensor technology means it knows when to switch to day light mode for a really impressive 450 lumen 'Dayflash'. And the parking feature means that it will power down if you haven't moved for a while. That seems a great way to conserve battery power on longer rides.

Performance on the road

I put this on a friend's bike and followed them up the road at different distances and in a range of conditions and there is no doubt that this has a really impressive light output. The default 40 lumen 'Steady' mode offers great visibility, but its Variable Lumen System means you can select anywhere between 80 and 10 lumen output in this mode. And the 5 lumen 'Group Ride Mode' sets the mood beautifully in any peloton, and is suitably kind to the retinas of your fellow riders.

'Dayflash' mode is particularly impressive. I often find myself setting off on early morning rides behind a host of weedy rear lights and wonder why most people bother to leave them running. There's no such issue here because this offers real punch, with the full 450 lumens behind it.

The side visibility is an important extra. The manufacturer suggests a 300-degree field of view, but mounted on your seatpost, it's probably effective over a 180-210 degree sweep.

Battery life is exceptionally good. I've been using this every day on commutes and a number of club rides for almost three weeks, and it has only just started to give the slow blue flash that indicates it's time for another recharge.

Stated run times go up to 100 hours according to the manufacturer. They say you'll get 48 hours in Flash 1 mode, although this also factors in the extra power required to operate in brake mode, so you can expect it to run for longer, if you aren't using this feature. The park mode means that it powers down when it senses that you have stopped and this also adds to the efficiency of these lights.

Value

If money is no option, then you might want to consider the Exposure Boost-R with ReAKT and Peloton. It is popular among long-distance riders and it scored a solid nine when Mat reviewed it. He was impressed with its runtime and visibility and it has many of the same features as the Moon Helix, though with an RRP of £100.

But if you want a good choice for commuting without the range of options then you could consider the Lezyne Strip Drive 300+ LED Rear Light, which at £40 is a great option. It is heavier at 75g but it's durable, has good runtimes and a good range of powerful outputs. Hollis gave it nine stars and says you would struggle to find a better option. I've been using one of these for years and rate them very highly for function and long-term durability.

If you want a budget option, then the Knog Plus Rear Light has an RRP of £18.99 and again scored a solid nine when Nick reviewed it. It does have a limited runtime in steady mode and just a 20 lumen output, but that should be enough for most commutes or as a back-up for longer rides.

Verdict

The Moon Helix Sense is a well-crafted, high-performance rear light, packed with features, although its single-button control may feel a little complicated. The brake sensor and light-activated daylight mode are nice touches, though perhaps not essential for all riders. For those seeking reliable, powerful illumination with robust build quality, this light offers excellent performance in any weather.

Verdict

Long runtime, exceptional visibility and an array of innovative functions make this a great performing rear light