One common question when it comes to bike taillights is “how bright of a taillight do you need.” Moon Sport’s answer to that question is the new Helix Sense taillights which are offered in two versions: Helix Sense 300 and Helix Sense 450. Not only are these taillights absurdly bright, but they also incorporate motion sensors to detect braking and warn others behind you. Retail prices are $69.99 and $80.99 for the Helix Sense 300 and Helix Sense 450 respectively. As the product names imply, the taillights are capable of 300 lumen and 450 lumen output. The lights also offer Moon Sport’s Variable Lumen System (VLS) feature which allows you to customize the intensity of each mode independently.  With their transparent red lens and rectangular profiles, both Helix Sense taillights also have 300 degree side visibility to help you be seen at any angle.

The Moon Helix Sense taillights combine impressive output with a modern COB LED rectangular design.

Retail Price$69.99 (Helix Sense 300) / $80.99 (Helix Sense 450)
Rating 8.9 / 10
Measured Weight (in g) 36 (Helix Sense 300), 46 (Helix Sense 450), 10 (seat mount)
Likes+ Absurdly bright
+ Sleek and modern COB LED design
+ Multiple mounts included right out of the box
Dislikes– Two-level battery status
– Single button interface can be a bit complicated
Where to Buy (US)Moon Sport


The Helix Sense comes in black and yellow cardboard boxes with a center cutout that allows you to interact with the taillights. Both taillights come with the same contents. Inside the box you’ll find:

  • Helix Sense taillight
  • Seatpost mount + angle rubber mount + two rubber straps
  • Saddle mount
  • Body clip
  • USB-C charging cable
  • Two zip ties

We were impressed that Moon Sport includes all the mounts with the taillights instead of selling them separately.


The Helix Sense lights use a miniaturized Garmin quarter turn style mount to quickly install and remove the taillights. It’s a simple but effective design that uses two protruding tabs that slide into corresponding slots. Moon Sport includes three different mounts with each taillight to allow you to attach the taillight to seatposts, saddle rails and even clothing / backpacks. The seatpost mount is a simple plastic design with hooks and rubber straps. There are two lengths of rubber straps included to accommodate different diameter seatposts. As with the Magicshine Seemee taillights, the seatpost mount works with both round and aero seatposts thanks to a simple center cutout. The additional body clip and saddle mounts are also simple plastic designs and allow you to relocate the taillights to your saddle, backpack, clothing or saddlebags right out of the box.

Moon Sport Helix Sense 300 / 450 Smart Taillight Review - Mounts
The taillights include three mounting options right out of the box: seat post mount (aero or round), backpack clip and a seat rail mount.


Visually, the Helix Sense 300 and 450 have nearly identical designs with rectangular profiles and COB LED strips. The Helix Sense 300 is slightly shorter than the Helix Sense 450 but has the same depth and width. There are four COB LED strips, two on the sides and a center section with most modes operating the LEDs together or the sides / center separately. The red transparent lens has a protruding design which helps the light achieve 300 degree visibility. On the sides of the light you’ll find Moon Sport’s reflective zig-zag graphics that are also found on their other products like the Rigel 700. Branding is limited to Moon debossed onto the lens and Helix Sense on the other side. On the rear of the light you’ll find a rubber cover for the USB-C charging port, a feature we’re happy to see and the Garmin style mount molded directly in.

Moon Sport Helix Sense 300 / 450 Smart Taillight Review - Side Photo
While the Helix Sense 450 is taller than the 300, both have thin rectangular profiles that hide well behind seat posts.

There is a single black rubber button on the face of the lens that controls all the operations of the taillight. As with other Moon Sport products there are quite a few features baked into the light. Holding the button for a few seconds powers the light on and off while a short press will cycle through the constant or flash modes. There is a two-level menu which separates the flash and constant modes which can be toggled by doing a quick double press. The user interface becomes complicated when you want to access the Variable Lumen System (VLS) and enabling the lockout mode. With VLS you can hold the power button in any mode to have it ramp between the minimum and maximum lumen for the mode, while releasing the button selects the current lumen amount. It’s a unique feature that allows you to customize the output modes of the taillight without the need of secondary apps.

The lockout feature allows the light to be “locked” to prevent it from turning on accidently while being transported or stored. It’s a common feature for bike lights but can be confusing for users as it makes it appear as though the light is broken (i.e. it only flashes briefly if you try to interact with it while locked). Additionally the brake sensor can be enabled or disabled by holding the button until you see the first flash. Moon Sport has also incorporated a small rear LED that illuminates green as a visual indicator that the brake sensor is active. As with other brake sensor taillights such as the Kryptonite XBR or Magicshine Seemee 150, the brake sensor while useful can lead to erratic runtimes which is why you may want to disable it.


The Helix Sense lights come pre-programmed with five output modes split between two constant modes and three flash options. Although you can’t change the flashing patterns, the built-in Variable Lumen System means you can adjust the intensity of every mode independently from each other. That’s one reason why the actual output modes have generic names such as mode 1, mode 2, flash 1, flash 2 and day flash. The Helix Sense 300 and Helix Sense 450 have the same mode options and nearly the same lumen per mode except for the brighter flash modes and longer runtimes of the Helix Sense 450.

The factory defaults of the Helix Sense 450’s two constant modes, mode 1 and mode 2, are 80 lumen and 5 lumen with 2.25 hr and 30 hr respectively. These correspond to a high/low setting and illuminate all the COB LEDs which is perfect for night time riding. The two flash modes are a night-time flash, where the side COB LEDs remain constant and the center COB LED strip flashes for a low-high effect while the second flash mode is a standard on-off pattern. The runtimes for those flash modes are 20hr and 26 hour respectively with 40 and 80 lumen outputs. Daytime flash is the most impressive output mode with an irregular flash pattern that alternates between 80 lumen and the blinding full 450 lumen for up to 11 hrs. As you’d expect, the Helix Sense 300 has the same flash mode but 300 lumen output and 13 hour runtime.

Moon Sport Helix Sense 300 / 450 Smart Taillight Review - Illuminated Photo
The Helix Sense 300 and 450 use dual COB LED stripes which illuminate the center LEDs and the sides separately depending on the mode.

The daytime flash mode is ridiculously bright and can nearly blind you if you look directly at it. Even the lower 300 lumen daytime flash is honestly overkill and is quite distracting for riders behind you. That said, it’s great for daytime riding on bright days if you ride in high traffic areas as it ensures you’re visible. Both lights also feature the “SENSE mode” which switches the taillight to a constant mode at full intensity if braking is detected while in any output mode. As with other brake sensor equipped lights, Magicshine Seemee 150 or Lupine Rotlicht, the brake sensor isn’t always accurate and can activate on rough roads or when adjusting positions on the saddle.We found that Moon’s calibration works well most of the time and can help alert cars or riders around you when you’re slowing down. The SENSE sensor can also be easily disabled which we’d recommend for longer rides, as the feature can lead to reduced runtimes.


Overall, we found the Moon Helix Sense taillights to be bright and feature packed. Both the 300 and the 450 lumen variation have modern COB LEDs with slender rectangular designs. Moon Sport includes multiple mounts with each taillight to allow them to be mounted on seat posts, saddlebags / clothing or even saddle rails right out of the box. Regardless of which version of the Helix Sense you choose, they are blindingly bright with daytime flash modes that keep you visible from long distances. The only downsides to the lights is that the user interface is fairly complicated, the lights have relatively high retail prices and the fact that there is no multi-level battery status indicator. That said, if you’re in the market for a bright and modern taillight with brake sensor the Moon Helix Sense 300 and 450 are great options.

Disclaimer: The product for this review was provided by Moon Sport. The views expressed on this website are solely those of the authors and are here to help people make an informed choice before a purchase. The authors or the blog itself does not get any monetary compensation from the product manufacturer or third-party websites/vendor links that are posted here.

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