One of the biggest changes when it comes to bicycle tail lights is the integrations of sensors and smart connectivity features. Tail lights aren’t just simple AAA battery operated lights with one or two output modes anymore, they’ve become smart devices. The Shanren Raz Pro is perhaps one of the smartest taillights on the market and was successfully launched from a Kickstarter campaign as “an expert bike taillight.” The Raz Pro has the technology to back the claim as it not only features brake and ambient light sensor but can also detect bumps and sync flash modes with other Raz Pros near it. Designed around 12 full color LEDS in a circular pattern, the Raz Pro boasts 60 lumen output and upto 48 hour runtime. With the bluetooth connected Shanren app, you can select any color in the RGB spectrum as well as fully configure the tail light. 

Not only is the Shanren Raz Pro a technologically advanced taillight but with an associated app it’s also one of the most configurable bike taillights we’ve used.

Rating 9.1/10
Retail Price$39.90
Measured Weight (in g) 20 (Taillight) / 10 (Seatpost Mount) 
Likes+ Highly configurable
+ Unique and eye catching output modes
+ Well calibrated brake sensor
Dislikes– Not bright enough for daytime use
– Proprietary magnetic charging cable
– Need to use app to access all features
Where to Buy (US)Shanren


The Raz Pro is shipped in a sleek white/black cardboard box with a round window in the center to show off the tail light. High contrast text and graphics provide an overview of some of the smart features and specs. Inside the box you’ll find:

  • Raz Pro Taillight
  • RX1 Seatpost / helmet bracket box 
  • Round/aero seatpost pad
  • Helmet pad
  • Two sets of mounting o-rings (short/wide)
  • Magnetic charging cable
  • Instruction Manual


Shanren currently offers two mounting options for the Raz Pro: a seatpost / helmet mount known as the RX1 and an optional seat rail bracket which is the RX2. While we didn’t get to try the RX2, we mounted the Raz Pro on our seatpost. The seatpost / helmet mount uses a quarter turn style holder with a dual o-ring design that is similar to computer mounts. Four hooks on the mount can be used in conjunction with the o-rings to secure the taillight to a seatpost or helmet. It’s a bit cumbersome to take the taillight on/off compared to the rubber straps you’ll find on standard tail lights like the Topeak Redlite Aero but works well. With the quarter turn style mount, the Raz Pro is easy to quickly install and remove from the mount though.

Shanren Raz Pro - Seatpost Mount
The Raz Pro uses a simple o-ring locking mount with o-rings to attach to round/aero seatposts or helmets


With a round shape and white lens color, the Raz Pro has a modern visual design to match the high tech features. Concentric rings of lighter gray breakup the white lens and give it a unique look. There are 12 LEDs arranged in a circular pattern along the center of the tail light that only become obvious when the tail light is on. While the tail light looks white when off, internal reflective elements ensure it glows the selected LED color when it is on. The Raz Pro isn’t particularly thin as the internal battery and protruding Garmin style mount account for about 75% of the 20mm thickness. There is also minimal branding on the tail light with the logo printed in a small font on each side of the housing.

Shanren Raz Pro - Adjustable Color
The 12 LEDs on the Raz Pro can be configured to any RGB color using the free app

Rather than a traditional micro USB port or a more modern USB Type-C port for charging, Shanren has integrated a proprietary magnetic charging port. The charging port has two magnetic prongs that are designed to snap the charging cable in place quickly. While the small magnets aren’t that strong, they work well to quickly position the charging cable. We don’t particularly like this type of design as it requires a proprietary charging cable which makes it hard to replace if you lose one or carry it with you if you ride away from home. One big advantage of this design is the impressive IP68 waterproof rating which means the taillight can be submerged under water in certain conditions.


The power button is located on top of the light. A single press of the button turns the taillight on while a long hold turns it off. Mode memory ensures the taillight always remembers the mode previously active when the taillight was last on. Cycling through modes can be done with a short press of the button while a double press cycles the tail light through a preset list of LED colors as well as one custom color. While the ability to set different colors is cool, we’d recommend sticking to the standard white/red colors when used on the bike. Additionally the tail light color can be changed by doing a quick twisting motion. What we like about these two shortcuts for changing the color is that you don’t need to solely rely on the Shanren app.


The Raz Pro boasts a number of build in sensors which allow the taillight to adapt and react to the environment and the rider. We also want to point out the fact that Shanren allows you to independently enable/disable the features through the app which allows for a customized experience. Note that Shanren doesn’t provide a way to enable/disable features per output mode, all eight output modes use the same configuration.

Brake Sensor: Utilizing a 6-axis accelerometer inside the taillight, the Raz Pro can sense deceleration and switch the taillight output to a specific mode. With the Raz Pro, the ‘brake mode’ is a full brightness constant mode. That means if you come to a stop in a flash mode, the taillight switches to a constant mode to attract attention. While this feature works, brake sensor implementations differ depending on the taillight brand as there are no industry standards for it. For example, the Magicshine Seemee 200 flashes, the Kryptonite XBR illuminates a specific brake LED, while the Lupine Rotlicht goes to full constant mode. That means while this is a useful feature you should still use caution as others around you may not know how to react. We found that the calibration of the sensor was well done with minimal false positives on the road.

Bump Sensor: By leveraging the same accelerometer as the brake sensor, Shanren has developed what they call a ‘bump’ sensor which can detect large bumps and warn others around you. It’s a unique feature but a bit unusual as well. When a bump is detected, the taillight switches to a constant white output. The color change definitely attracts attention, but unless other riders are familiar with the Raz Pro, they likely won’t know how to interpret the color change. We found that it was surprisingly consistent on the road and only triggered on larger bumps.

Ambient Light Sensor: In contrast to the move toward daytime visible lights, the ambient light sensor in the Raz Pro actually shuts the taillight off in bright conditions. The light automatically turns back on in darker conditions to provide illumination. By default this feature is actually disabled, which is likely to avoid confusion and complaints about the taillight shutting off. It is a feature that could be useful for riders looking to conserve battery during the day. However, we would have preferred the ambient light sensor to be programmed to automatically switch between daytime / nighttime modes instead like the Bontrager Flare RT and Light & Motion Vya Pro

Team Sync: Perhaps one of the most unique features of the Raz Pro is the ‘team sync’ feature. This is a very clever feature that allows multiple Raz Pros to flash in sequence. If you’ve ever been in a group ride or behind multiple riders, you know that it can be a bit overwhelming to see multiple taillights in different flash modes and brightness. As the name implies, team sync allows multiple riders to have taillights act in unison which not only improves the safety of riders in a group but makes the group look larger and more visible. 

The feature doesn’t need WIFI or an active app connection to work either, just close enough proximity and for the Raz Pros to be in the same mode and color setting. With the app, this feature can be adjusted to require a password to prevent it from syncing to random people’s Raz Pros as well. This feature isn’t useful if you’re just buying a Raz Pro for yourself, but if you can convince your local club or riding buddies to also use the Raz Pro, it’s a cool feature.


Out of the box, the Raz Pro is configured to cycle through five different modes. Those modes are: fireworm breathing (pulsing mode), flash, double flash, sustained (constant mode) and slow flash. Using the Shanren app, you can also add an additional three modes: comet (full power then gradual fade), SOS, and triple flashes. Unfortunately, Shanren doesn’t provide the estimated runtime or lumen per mode but the instruction manual states runtimes vary from 24hr in flash mode to 46hr in slow flash. With the app you can re-order or even add/remove modes to customize the output modes from anywhere between a single mode to all eight options. Our only concern is that this configuration option is only available through the app – which means if Shanren drops support for it in the future, you may lose functionality.

The output of the taillight across all modes can be switched between low / normal / high using the app – with normal mode set by default. We didn’t feel like there was a significant difference between the modes and just left it in normal mode. While the claimed output for the Raz Pro is 60 lumen from the 12 LEDs of the tail light which is on par with other taillights on the market, we didn’t find it bright enough for daytime use. Also, we  would have preferred a COB LEDs design like the Magicshine Seemee 60 which has a more uniform and even glow over the 12 separate LEDs of the Raz Pro. That said, the large size of the taillight and protruding shape of the lens do mean the Raz Pro is visible from as far as 270° which is a great safety feature and works well at night.


Overall, we found the Shanren Raz Pro to be an advanced and highly configurable taillight. With brake, bump, and an ambient light sensor integrated into the tail light, the Raz Pro can react to the environment. We found the brake sensor surprisingly well calibrated with predictable behavior on the road, while the bump sensor was a bit more sensitive to some impacts. The ambient light sensor isn’t particularly useful unless you want to preserve battery as it turns the taillight off in daylight. Also the team sync is a useful and unique feature if you have multiple Raz Pros or can convince your riding buddies to buy one. The app that makes it easy to configure the taillight – everything from the order of the output modes to the LED colors. That said, we don’t think the 60 lumen taillight and 12 LED design is bright enough for daytime use, however, as a secondary or nighttime taillight, the Raz Pro offers impressive technology and configurability.

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