Although Fabric is best known for their innovative bike saddle range, they’ve applied many of the same design principles to their bike accessories. In this post, we’ll be looking at Lumasense V2, the latest version of Fabric’s Lumasense smart bike taillight. As with their saddles, the Lumasense V2 has a simple yet modern design and technical details that differentiate it from other tail lights on the market. When the Lumasense V2 senses deceleration, the light switches to the 100 lumen boost mode to ensure you remain visible. This is a smart feature that can improve riders visibility as they approach intersections or make sharp turns.

The Lumasense V2 is a competitive taillight with well-calibrated brake sensor and great visibility for both day and night riding.

The Lumasense V2 also has a number of improvements over the original version including improved side visibility, runtime and a higher output 100 lumen boost mode. Visually, the Lumasense V2 has a cylindrical form factor with COB LED design that has a uniform glow and great side visibility. The retail price of the Lumasense V2 is $40 which is inline with other smart taillights on the market in the 100 lumen maximum output range. A tool-free rotatable mount also allows you to quickly mount the taillight in a variety of locations on the bike.

CategoryBicycle Tail Light
Rating 9.0/10
Retail Price $40
Measured Weight (in g) 50 (total): 34 (light) + 16 (mount)
Likes+ Great side visibility
+ Unique cylindrical form factor
+ Well calibrated braking sensor
Dislikes– No mode memory
– Only mounts on round seatposts
– Lacks a clear battery status
Where to Buy (US)Fabric


Fabric packages the Lumasense V2 in a simple cardboard box with bright graphics. The Lumasense is clearly visible through a plastic cutout which allows you to easily interact with the light. Inside the box there is a tidy cardboard tray that holds the lights and mounts in place.

In the box you’ll find:

  • Lumasense V2 tail light
  • Seatpost mount + rubber strap 
  • Micro USB charging cable
  • User manual


Fabric includes a simple plastic mount that attaches to round tubes with a rubber strap. The rubber strap feels thick and has a talon design with two hooks on one side and a single hook on the other for easy attachment. The mount has a two prong design that securely holds the Lumasense V2 in place. A groove on each side of the mount also allows you to slide the light side to side for more flexible positioning.

Fabric Lumasense V2 - mount
Simple rubber strap mount and bracket

Something we didn’t initially realize was that the Lumasense V2 can also be rotated a full 360° around the mount at fixed increments. This allows the Lumasense V2 to be mounted horizontally or vertically. It is easy to overlook this feature, as it takes quite a bit of force to rotate the tail light on the mount. One thing the mount lacks is an angular offset to account for the seatpost angle. This results in the tail light being angled slightly downward as seatposts are angled backward slightly, which reduces its effectiveness.


Visually, the Lumasense V2 has a distinctive cylindrical shape that is close to a standard AAA battery dimensionally. The round shape is complemented by the COB LEDs which partially wrap around the sides for improved side visibility. The thin diameter of the Lumasense also means that it is easily concealed behind the seatpost for a clean look. The light is made from plastic materials which is not surprising at this price point (the Lupine Rotlicht is one of the few metal lights we’ve seen) and yet still feels lightweight and well built. With the IPX5 rating the taillight should also easily survive daily use even in wet climates.

Fabric Lumasense V2 - Power button
Power button illuminates red when the battery is less than 15 percent

The power button is located on top of the light and is large enough that it is easy to use even with gloves. As with other Fabric lights, a 3-second long hold powers the light on and off while a single short press cycles through the four available modes. There is no mode memory though, which means the light always defaults to the same flashing mode when turned on. This can be particularly annoying if you don’t like the default, as you’ll always need to change the mode each time you power it on. We also found the 3-second long hold to power the tail light on and off a bit long compared to other tail lights on the market making it a little awkward to use.


The Lumasense also has an integrated brake sensor, which is designed to switch the current active output mode to a boosted 100 lumen mode when deceleration is detected. The feature has become more common in tail lights, and Fabric has done a good job with the calibration. Our tests showed the brake sensor worked consistently when coming to a stop but it would also occasionally get triggered on potholes or bumps. In general, we are on the fence about the effectiveness of brake sensors, but it is hard to deny the fact that the 100 lumen boost mode of the Lumasense definitely attracts attention. Since the brake sensor cannot be disabled, it will reduce the overall runtime if it is triggered often.


Fabric programmed the Lumasense with two steady output modes and two flash output modes.  There is a high and low setting that have claimed runtimes of 8 and 15 hours respectively. There is also an irregular flash (the Disrupt mode) and a standard flash with claimed runtimes of 20 hours and 10 hours respectively. Fabric doesn’t publish the lumen output per mode, but in non-boosted mode, the Lumasense has a 30 lumen output. Based on runtimes, we suspect low mode is close to 15 lumens, while the flash modes are close to 30 lumens. With many tail lights exceeding 150 lumens these days, the 30 lumen output doesn’t sound impressive on paper but proved to be plenty bright on the road.

Fabric Lumasense V2 - visibility
Wrap around LED design provides good side visibility

The COB LED design with a uniform grid of LEDs on a single board also means that the Lumasense V2 has a uniform glow that looks good during the day or night. Side visibility is particularly excellent as the lens partially wraps around ensuring you remain visible even at higher side angles. We preferred the irregular flash mode during our rides, and found the other modes less useful. Particularly, with the lack of mode memory with the Lumasense V2, this meant we often had to cycle through the modes to get to our preferred mode.


Overall, we found that the Fabric Lumasense V2 is a well designed and calibrated smart tail light. The lightweight and compact cylindrical design of the Lumasense V2 means it will easily hide behind your seatpost for a clean look. While the taillight mount can be rotated,it doesn’t have an offset to account for the angle of the seatpost and Fabric doesn’t currently offer a mount for aero seatposts. We found that the 30 lumen output worked well during both day and night, and that the 100 lumen boost mode during deceleration was an excellent way to attract attention. Note the tail light does lack a battery status anc like most USB rechargeable lights, it only has a low battery indicator. Nevertheless, we found that the Lumasense V2 is a competitive tail light with well-rounded features and premium build quality.

Disclaimer: The product for this review was provided by Fabric. 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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