Hot!
- Highly visible from 2km away, even in bright sunlight
- Great for day or night riding
- ANT+ and Bluetooth smart
- 5 visibility modes: 3 daytime, 2 nighttime
- Fits BlendR rear magnetic mount on Bontrager Circuit MIPS helmet
- IPX7 waterproof rating and updated easy open/close USB port
- Long-lasting USB-rechargeable battery
- Connects with Bontrager Transmitr and select Garmin computers
Not
- Clip mount for saddlebag must be purchased separately
Also Available at Amazon: https://amzn.to/2DIbm7q
Cost: $59.99
How Obtained: Company sample
Availability: Online and retail
RBR Sponsor: No
Tested: 1 month
Tech Specs:
- Both day and night flash or steady modes
- Features a CREE® LED
- USB Rechargeable
Always On
I’ve been using Bontrager’s Flare R since it launched about 3 years ago and purchased the Flare RT back in May. Recently, Bontrager came out with a new and improved version of this rear light and they included it in my swag bag at the Trek Women’s Advocate summit. So I was able to compare 3 generations of the light.
The new light is 36% smaller, 30% more powerful, 40% more Lumens, and runs 20% longer than its predecessor. They also updated the USB port to seal out water. Wow, didn’t think they could improve this great light.

Bontrager’s ABCs of awareness is A=Always on, B=BioMotion, C=Contrast. Always on means lights both day and night. I’ve been running a rear light consistently for over 5 years and added a front light (Bontrager ION 800 RT) more than a year ago. I know for a fact that riding with daytime lights has saved me from getting hit numerous times. Drivers just see you better and sooner. The statistic that 80% of cycling accidents occur during the day made me realize that I needed to be noticed by drivers.
When cars added daytime running lights accidents were reduced by 25% and for motorcycles a drop of 13%. From Trek’s research with Clemson University, it showed that the best thing a rider can do to be more visible on the road is to ride with a flashing light. Studies have shown a 270% increase in driver recognition of a cyclist with a flashing rear light compared to without. An additional study showed a 33% decrease in accidents for cyclists equipped with daytime running lights.
Focus, Flash, Range
There are three components that make up an effective daytime running light.
- Focus. Bontrager intensifies the light beam to extend its range. Some lights may appear bright but, in the daylight, may not be noticed.
- Flash. To increase noticeability, the Flare RT uses a varied output and an interruptive flash pattern (90 Lumens).
- Range. This rear light is visible from 2km away in daylight. This gives drivers more time to react to your presence.
Checkout the Bontrager’s videos on Daytime Running Lights and Clemson University research partnership.
Ride Longer
The new Flare RT provides a full 12 hours of runtime with all-day flash mode and battery save mode provides 30 minutes of additional runtime when battery life reaches 5%.
Flash modes
Day flash: 90 Lumens – 6 hrs Day
All day flash: 45 Lumens – 12 hrs
Night flash: 5 Lumens – 15 hrs
Steady mode
Day steady: 25 Lumens – 4.5 hrs
Night steady: 5 Lumens – 13.5 hrs
Additional features of the Flare RT include a built in ambient light sensor to automatically set the light to the best mode for conditions. A Lock Mode can be set to ensure the light always stays in the preferred mode.

Wireless Control via Garmin Edge, Bontrager Garmin Edge and Bontrager ANT+ Devices
The Flare RT connects to certain Garmin Edge models, Bontrager Garmin Edge and Bontrager ANT+ devices to turn lights on/off, select mode, view real-time light battery status, and more.
You can control this light wirelessly using the optional Transmitr ANT+ remote (additional $39.99). The Transmitr wireless remote controls up to 7 Transmitr-ready devices and attaches to the handlebars. One interesting use for the Transmitr is to pair with multiple Flare RT rear lights for turn-signal configuration.
If you already own a Garmin Edge (select models) or Bontrager Garmin Edge, you don’t need to buy the Trnasmitr. The light is easily paired for wireless control and battery status. When I reviewed the earlier model, I noticed the battery life was reduced when paired with a Garmin. I figured it was due to the Bluetooth connectivity with the Garmin and light “talking” to each other constantly. According to the engineers who developed the new Flare RT, “variance in the temperature would cause more fluctuation in run time than if connected to a Garmin.”
Mount to Your Bike or Helmet
The IPX7 waterproof rating and updated USB port protects the light from downpours, tire spray and even temporary immersion up to 1m. So, no worries using it on your seat post or helmet. The Flare RT comes with a rear Quick Connect bracket to attach to the bike or slide it on the BlendR Magnetic mount that comes with the Circuit MIPS road helmet (see my review). An optional Tail Light Seat Pack clip ($4.99) lets you mount the light to your saddle bag. Just make sure that the light is perpendicular to the ground to maintain proper visibility to drivers.

The Bottom Line
With distracted driving on the rise, being visible on the road is the number one concern of mine. Thus, I never ride without daytime running lights both front and rear. I had been using the original Bontrager Flare R rear light for over 3 year and now started using the new version of Flare RT on my Circuit MIPS helmet. I feel more visible to drivers which translates to being safer on the road. The new light is now lighter weight, smaller and more powerful than its predecessor. Being rechargeable via USB and visible from 2km away during the daytime, Flare RT is the perfect light to choose for all your road riding.
“The statistic that 80% of cycling accidents occur during the day”. 80% of bicycle riding probably occurs during the day, hence…
“I know for a fact that riding with daytime lights has saved me from getting hit numerous times.” I switched to lights this year when I got a trike because it is lower to the ground and I felt less visible. The interesting thing is I never rode with lights on my bike unless the conditions were low visibility (I never ride at night), and I never once felt I was going to get hit. Lights definitely improve visibility, but I never felt invisible on my bike, possibly because of my highly visible clothing.
Your feelings about your levels of visibility to drivers are likely less important to them than is your actual visibility. Because, after all, drivers care little for a cyclist’s feelings or self-perceptions.
What is most impressive about this light is that it does the things that the actual scientific research suggests are necessary to increase a cyclist’s visibility to drivers.
I’m sure all of us would agree that today, a significant proportion of drivers are likely paying less attention to the road than they should — hence the advent of distracted driving legislation in some areas. Therefore, something (like the FlareR light) that so effectively increases a cyclist’s visibility, should be a must-buy for any cyclist that shares the road with cars and trucks. For the purchase price, the benefits are certainly worth it.
It may not be is important to use a light like this if a cyclist can limit their riding to protected trails or separate bike lanes though.
Can’t agree more that cyclists riding with automobile traffic need flashing front and rear lights. As stated above, after riding in traffic for several hours, you have a front row seat to see how distracted motorists are nowadays. Distractions include cell phones, applying makeup and eating and drinking. I use Cygolite products (Trident Xtra 1300 on the front(1300 lumens), and Hotshot 100 (100 lumens) on the rear. People are inherently inquisitive especially about things they don’t normally see in their everyday driving experience and that includes flashing, blinking lights. Over the last few years I have noticed more and more cyclists in my area using the flashing lights front and rear during the day. There is no downside to a cyclist making themselves more noticeable to drivers. I also recommend wearing high visibility clothing and ditching the black jerseys.
It’s very strange thing – both: “Flare RT” and “Ion 200 RT” are same in price and size. BUT Ion 200 RT has 200lm brightness vs Flare RT has only 90lm !!!
Also: Ion 200 RT has more battery capacity!!! Ion 200 RT running up to 14,5 hours (solid-on mode), but Flare RT just up to 4,5 hours in solid-on mode!!!
So you can buy two pieces of EQUAL price but one of this several times more powerful then another!!!! WHY must I pay equal price for such pieces??? I prefer to buy “Ion 200 RT” then glue to it an red-glass cover and use it as rear light for longer time (in minimal-mode settings). Why I need Flare RT?
Per current specs on the Trek/Bontrager website (www.trekbikes.com):
Ion 200 RT: 200LM-1.5hrs, 100LM-3hrs, 5LM-14.5hrs
Night Flash-30hrs, Day Flash-12hrs
Flare RT: Steady modes: 25LM-4.5hrs, 5LM-13.5hrs
Flash modes: 90LM-6hrs, 45LM-12hrs, 5LM-15hrs
The only meaningful comparison is the steady-mode 5LM spec, which is actually slightly better for the Flare RT.
And they use the same battery, listed as a “420Li-Poly”, so, bottom line, they are both maximized to use the same resource for the intended purpose, so your strategy, though admirable in its insights, will not improve the off-the-shelf product for its intended use.
Are the mounts for the newer Flare RT and older model Flare R the same design, i.e. interchangeable? Thank you.
It appears from the product description that the mounts sold for BT Flare lights will work with all BT Flare lights, so it looks like they are interchangeable.
Example:
https://www.trekbikes.com/us/en_US/us/en_US/equipment/bike-accessories/bike-lights/bike-light-accessories/bontrager-flare-round-mounting-kit/p/21488/
“Replacement or extra mounts for all Bontrager Flare rear lights”
I’ve just gotten into the biking world from backpacking and have purchased a Rocky Mountain Growler. Went looking for a bike light and found this one that I really like. Anyone have any other suggestions? https://tonque.myshopify.com/
can battery be changed internally??
I was hoping to get information about how long it stays in standby mode with Garmin Edge. Should use ANT+ connection which is very battery saving.