Bontrager Flare RT & Ion 200 RT Connected Bike Lights In-Depth Review

Bontrager has introduced a new far smaller and much cheaper variant of their popular Flare RT connected bike lights.  These $59 individual front and rear lights connect via ANT+ to supported head units to automatically turn on when you start a ride, and turn off when you end a ride.  You can also control functionality, like light modes, from the head unit itself.

Bontrager is hardly new to the connected lights game; in fact, they were actually the first company to introduce such connected lights using the ANT+ device profile (Garmin then followed a bit later), back in April of 2015.  The initial iteration of the Bontrager Flare RT and Ion RT was actually quite good – and they even had a nifty remote control (still do if you want it) to control the lights.  But these days most riders will likely be using their Garmin bike computers to do so.

The main focus for the new Flare RT and Ion 200 RT lights isn’t so much folks needing massive amounts of light (meaning, it’s not really best for mountain bikers), but rather what the industry roughly terms as ‘safety lights’.  In essence, it’s more about vehicles seeing you than you having the path in front of you lit-up like a stadium.  For those living in cities, it’s perfect – whereas for those living on farm roads…not so much (as I found out).  They’re also perfect as daytime running lights on the bike, since they’re so tiny you’d barely notice them weight-wise or size-wise.

Bontrager sent over a loaner pile of the new lights to try out.  This included both the Flare RT/Ion 200RT lights I’m reviewing here, as well as the Ion Pro Series lights that I’m not focusing on here.  The Pro series lights are also connected, and are quite a bit beefier in terms of size and lumen throw-down (an official term, obviously).  Maybe if there’s interest I’ll also do something on the Pro lights down the (well-lit) road. As usual, once I wrap things up I’ll shoot them all back to Bontrager.

With that – let’s begin!

What’s in the box:

I should probably preface this section with helping you understand the confusing naming scheme that Bontrager has come up with.  That, in turn, might help you try and navigate this review a bit more.

Ion Pro RT: Elongated front light announced this month
Ion 200 RT: Tiny cube front light announced this month (this review)
Ion 350/450 RT: Clunky-looking front lights announced a year or two ago
Ion 700 RT: Cigar-like front light announced a few years ago
Flare RT: Tiny cube rear light announced this month (this review)

Oh, there’s one catch though: Sometimes the Flare RT isn’t this Flare RT. Sometimes it’s an older Flare RT. See, the company actually renamed the product the same thing – an Apple-like ode, without any clear generational or year identifier.

Thus, it’s confusing AF.  You’re welcome.

All you need to know is you want to look for the squarish one, and not the roundish one. Got it? Good, let’s begin unboxing (because the box is actually rather clever).

Here’s the back of the package, which includes a fancy chart to figure out how far away you can see the lights at various brightness levels and flashing modes:

Next, we’ve got the lights inside.  In my case, this is a twofer pack, which saves you a full $5 over the cost of buying them individually. That gets you three $1.50 Costco hotdogs + soda combos…just sayin’.

The packaging is actually fairly clever, since almost everything you need is visible immediately, with only the USB charging cable hanging out on the edges in that little cove.

Here’s all the parts on the table:

A closer look at the two included mounts shows a very slight difference for front and rear.  The rear one is tapered a bit so that it counteracts the slant of your seat post to keep the light level.

As for the lights themselves, they’re tiny – about the size of a strawberry (not the crazy big strawberries, just a normal strawberry):

There’s also a manual in there with all of the various mount options (which I’ll dive into later):

And finally, weight-wise, here ya go.

Interestingly, I think Bontrager might be showing light+mount on their official weight listings. They show 32g/33g, whereas I show 23g, sans-mounts.

How it works:

By and large, the entire point of buying Bontrager’s connected lights is to have them…connected.  But, that doesn’t mean you can only use them in a connected state. You can use them just fine sans-connection (mostly, as I’ll explain).  In short, there are basically three ways you can use these lights:

A) Just as normal lights: Press buttons on lights to turn on/off, and change settings
B) Connected to a head unit: Such as a Garmin device that can control them
C) Connected to Bontrager’s smart remote: Allows you to control them as well, using a tiny remote on your handlebars

I suspect the vast majority of people here are going with ‘Option B’ above, because there’s an overwhelming chance that if you’re reading this you’ve probably got a head unit that can control said lights.  But because you have to eat your vegetables before desert, we’ll start with the boring way, which is just double-pressing the button on the top of the lights (as the manual notes: just like a mouse double-click).

You can then long-hold to turn it off, or, press the button quickly to cycle through all of the different modes the lights have.  It’s really that simple. There’s only a single button, though you can do some ultra-long hold presses to get things reset and such.

There are the following modes for the rear light (Flare RT):

Day Flash  – 90 lumens for 6 hours
All Day Flash – 45 lumens for 12 hours
Night Flash – 5 Lumens for 15 hours
Day Steady – 25 lumens for 4.5 hours
Night Steady – 5 lumens for 13.5 Hours

And these are the modes for the front light (Ion 200 RT):

High – 200 lumens for 1.5 hours
Medium – 100 lumens for 3 hours
Low – 5 lumens for 14.5 hours
Night Flash – 5 lumens for 30 hours
Day Flash – 100 lumens for 12 hours

As an interesting note – when the battery drops below 5%, the unit automatically adjusts the brightness to 50 lumens. This gets you an additional 30 minutes of battery time beyond the stated times above.

Next, pairing to a head unit.  In case of all Bontrager RT lights, they all support ANT+ connectivity using the ANT+ lighting profile. At present, to my knowledge that’s only Garmin that’s implemented it.  Others have talked about it, such as Sigma, but haven’t yet implemented it.  Anybody can implement it, it’s no different than implementing other profiles like power meter or heart rate sensor support.

To pair the Bontrager lights to your Garmin, you’ll head into the sensors menu and add the ‘Lights’ sensor type. Both lights show up as their proper front or rear lights within the menus.

This will create a ‘light network’, which essentially allows all the lights to act cohesively together. You can control them as a formation, or individually if you want.

There are essentially two configuration options for how to control lights.  You can have them automatically turn-on when you power on your Garmin, or you can have them automatically turn-on when you press start:

I’ve set mine for when I press start, so that it’s not burning time while I prep my bike.  Also, one very distinct downside to this setup is that if you’re on the trainer indoors the lights will automatically turn-on. You can disable them entirely via the menus, but that’s not really an ideal solution.  More ideal in my mind would be a tie-in with GPS. If using GPS, then enable them, if not using GPS then disable them.

As I noted earlier, I did find issues with the default Garmin control panel for lights and seemingly overriding the manual button presses when in full formation mode to get in the steady-on mode in some situations.  If you disabled the full formation and went into individual light control mode on the Garmin, the settings seemed to stick.

The other option is to simply grab the Bontrager Connect IQ app (free), which is available for most Garmin Edge devices:

This app gives you a bit more control over the lighting modes, and the settings seem to stick properly. It’s easy to access as well anytime via swiping down from the top – just like you would access the weather.

All of this works just fine and dandy – and makes it easy to use the lights once setup.  Also, when you power off the head unit, it’ll automatically turn off the lights as well.

Finally, let’s talk battery and battery life – starting with charging. To charge the units you’ll grab your favorite micro-USB cable, or use the excessively short micro-USB cables that came with it.

As for battery life, that’ll depend vastly on which specific mode you’re in. If you’ve got the units on full blast (non-blinking), it’ll last far less than differing blinking modes.  That’s no surprise, blinking saves a ton of battery life on most bike lights.  Of course, the challenge to blinking is that many European countries require steady/always-on for usage (which takes more battery life).  But that gets into a bit of lighting religious debate that won’t be solved here.

In my case, I’m using it in a solid-on full-blast configuration.  In one test I did for battery depletion I charged both front and rear lights to 100%, and then got going on my ride. I probably had a few minutes of getting things setup before I started my ride (where the lights were on), but not much more than that.  At the 2 hours 00 minutes 04 seconds marker, the front light powered off, exactly at the specified 2-hour threshold (90 minutes full brightness + 30 minutes battery reserve) for this light in this configuration.  The rear-light meanwhile stayed on and appeared to have more battery – and didn’t reach a low-battery warning state.

I haven’t tested the blinking modes since solid-on lights are required here, though given the unit met specs precisely for the solid-on mode, I don’t doubt the company has the battery specifications correct.  Of course, it’s likely that things like temperature would impact battery life as well.  In my case, I tested on a warm summer night, whereas I’m sure if I tested in the dead of miserable winter, it’d undoubtedly be lower.

Brightness and Visibility:

Probably the most important parts of lights is whether or not you can see things with them, as well as being seen.  In the case of these lights, we’ll start first with what the rider can see.  I rode in a variety of conditions, including city riding, country riding, woods, day-light, dusk, and full-on darkness.  Basically, everything I could think of.

Overall they were good, but given the size things are also a little bit limited as well.  I’d rate them as follows:

Day Riding Anywhere: In this situation, it’s about others seeing you, the lights provide no visible extra light on the ground on a sunny day.

Night City Riding: Perfect, zero issues, and provides just enough light to fill in the cracks in the road and avoid them.  The city provides most of the ambient light for streets.

Dusk: No problems here either – same as night riding, since there’s still a bit of waining light, these lights fill in the gap.

Night Country Road Riding: It’s OK – but ONLY if you’re in the 200 or 100 lumen modes, NOT the 30-minute battery saver mode.

Night Dark Wooded Paths Riding: Same as road riding, but definitely not ideal for mountain biking with any quick trail work. The reach of the light beam just isn’t far enough to get the details you want, so there’s an element of trusting that the road is still actually road (that’s missing in mountain biking). Whereas on bike/running paths surrounded by trees, it’s darker, but you can generally still trust that the pavement is the pavement.

The basic lesson here is that the lights are fine on any pavement surface as long as you’ve got the two full brightness modes on.  The 30-minute (50 lumen) battery saver mode is simply not enough light to do anything except act as a safety light so others see you (which is still incredibly valuable).

So why not show a bunch of photos for the lights?  Because for the most part, photos of bike lights are fake news. It’s all photography tricks.  Every single camera will shoot/show the lights differently.  And most cameras (unless in a full manual mode), will shoot each light differently as they’ll automatically compensate for it.

The only way to do this in any meaningful way is to shoot all the different lights at the exact same time in full manual mode (on camera), and without any other changes in the environment.

For example, here’s a shot I did of the lights against one of the I.Amsterdam signs.  It might look like the light is throwing out a fair bit of light, right?

Kinda, it’s really more the phone is exposing it longer – thus, making it look brighter than it is (as is the waning sky).  Sure, there’s a fair bit of throw there from the lights, but it’s because it’s exposed for 1/4th a second.  If I exposed it for a full second, it’d probably look like day light out.  In the above setting, it’s actually in the 30-minute (50 lumen) saver mode.

Anything and everything you see photographically in any light review is 100% based on the settings the camera person selected.  That person can try and mimic what they see in real-life, but it’ll never match precisely.

Compare that to this GoPro shot taken from a video. It was shot at 30FPS (thus, 1/30th a second), and even though it was shot some 15 minutes earlier, it looks far darker (I’m coming towards the camera, that white dot to the left).  Oh, and the light? At this point it’s in the 200-lumen full brightness mode – far brighter than the above photo/scene.

Not only that, the two lighting conditions were flipped. The first one was taken later at night, and the second earlier with more light (both ambient and the Bontrager unit itself).

Here’s a photo below taken just a moment before the photo above, looking towards the setting sun versus away from it:

Again, a huge difference in what things look like.  You can see the visible light on the ground from the Ion 200 RT though in front of me.

As for others seeing me (or, me seeing my bike), no problems there.  For example, here’s me at dusk riding away from the camera (a GoPro). At this point I’m probably 150-200m away:

And here’s me turning around at roughly that same point and facing the camera:

And then much closer as well:

Again – it all comes down to cameras used.  The below shot was taken perhaps 5 minutes earlier with an iPhone X – and you can see just how much brighter the sky is, and in this specific photo below I’m actually even facing the darker portion of the sky too.

My entire point here is twofold:

A) Visibility of you: No problems here, no matter the conditions.
B) Visibility for you: Good for city riding or places with ambient light, mostly OK for dark riding as long as on highest brightness levels.

Though I suppose my real point is more simplistic: Taking photos of lights doesn’t do much for a review.

All the mounts:

Now I didn’t talk about mounting in the initial section, because I wanted to save it for later. Now is later.

The units come with little bite-sized mounts in the box, which you saw in the unboxing section.  And by and large, these mounts work great. Really, they do. There’s a little bit of extra strap length in some cases on some seat posts, but hardly a big deal, and you could easily trim it if you really wanted to.

Here’s the front mount, mounted:

And here’s the rear mount. You’ll notice in the case of the rear mount that there’s a tiny tilt built into it, to counteract the slanted nature of seat posts.

But this isn’t all the mounts that Bontrager has put together. They’ve got other stem replacement kits that allow you to mix and match Garmin quarter-turn mounts and Bontrager mounts.

You can see below the stem portion, then a middle piece that slides over your bars to allow either a Garmin or GoPro-style mount below it.  Alternatively, if you look above, at right is a snap piece that allows both a GoPro/Bontrager light and Garmin mount concurrently.

I’d love to see one other option here though, in particular perhaps a GoPro to Bontrager mount adapter sold separately, allowing you to easily pop it on existing out-front mounts that have GoPro adapters below them.  The below adapter is part of the stem kit, and is exactly what you need, but only available in the entire stem kit which is much pricier.

GoPro mount adapters have pretty much become the universal standard for mounting stuff on your bike, especially cameras and lights (Cycliq and Garmin both use them), and they’re found on almost all out-front mounts these days.  I’d expect a small piece of plastic adapter wouldn’t cost much, but would make a lot of people happy. [Update: Turns out you can buy it separately…at the mere cost of $25USD].

Feature Comparisons:

(Above left to right: Garmin RTL510, Cycliq Fly6 CE, See.Sense ACE, Bontrager ION 200 RT)

Smart lights are becoming more and more common, with numerous players in the industry making them – and most all of them are using open standards to communicate.  For example: Bontrager, Garmin, See.Sense, and Cycliq all use the ANT+ lighting standard to allow lights to be controlled from any ANT+ capable unit that implements the profile.

But while each company adheres to the specification, each company also has differences in what they have as overall features.  For example, Garmin’s lights tend to fall on the bigger and brighter end of the spectrum (and more costly), whereas the latest Bontrager and See.Sense units are smaller and more affordable.  Of course, Bontrager also makes the bigger lights as part of the Pro series too.  See.Sense has far more connected phone tricks as well, such as theft detection and sending data to urban planners. Then you’ve got Cycliq, which makes the combination bike light and camera units, the Fly6 CE/Fly12 CE series.  And lastly, Garmin also makes a combo – theirs being the combination radar and bike light, the RT510.

Here’s a quick comparison chart I whipped up with the main offerings from each company.  When you get into battery modes things get kinda crazy, so I tried to simplify here into the max battery life for solid and blinking (most companies have numerous modes for each).

Perhaps down the road I’ll create a new product comparison database category…but today is not that day.

Ultimately, like most product categories, it’s really going to come down to what your specific riding conditions are and what you value most.  If you’re riding darker routes, then the Bontrager Ion Pro or Garmin series is probably a better bet.  Whereas if you’re more in city conditions, then the smaller Bontrager or See.Sense units probably make more sense.


The thing about connected bike lights is that they’re easy to make fun of.  People will simply say ‘Just press the button on, stupid’.  And sure, that’s an option.  But if you bike commute every day in the early morning or evening hours, there will undoubtedly be days you simply forget to do that – especially the rear taillight that you wouldn’t likely notice immediately (or days when your brain isn’t fully caffeinated).  These products aim to eliminate that safety risk.

Additionally, as Bontrager points out – they really want folks using these smaller lights as daytime running lights, just like cars do.  In blinking modes, these lights get really solid battery life – far longer than your head unit does.  The idea that you can just start your Garmin and these lights automatically turn on when you press that button (and turn off afterwards), is definitely safety-focused (even if you think it’s silly).

I don’t really have any major complaints here with the new units except the confusing naming scheme – I really like them technically, and I suspect I’ll pick up a set to keep on my bike.  About the only downside that I found is that while the default Garmin app generally works OK with the units, you can’t seemingly set an entire light formation to stay solid-on from the control panel, only individual lights if you separate them out.  The Bontrager Connect IQ app solves this though, so it’s rather minor.

Ultimately – for the $59 each price point, these finally fit the bill from Bontrager. They bring them to a price point slightly cheaper than the existing See.Sense ICON+ lights (albeit with less features), and with a Trek distribution network that hopefully makes them easier for folks to pick up and make themselves more visible.

With that – thanks for reading – and feel free to drop some questions below!

DC Rainmaker :

View Comments (142)

  • I'm not a fan of connected, smart lights. It's too much trouble setting them up and fussing with them when a push of the button will turn on/off. I've been in high tech all my life and when I'm on the bike, I want to ride, not troubleshoot my lights. That said, I do have the latest Garmin and Radar which I do fool with and love but with rear lights or any light I just want it to blink until I say stop blinking.

  • Loved the review Ray, thanks, so I went out and got a set the other day - great lights, really happy.

    Paired them with my edge 520, worked like a charm, and then assigned control to the Di2 buttons on the top of my ultegra brake hoods.

    That was easy too. But i can't find any explanation anywhere of how Di2, my Garmin and the lights actually work together!

    There are only two light functions available in the settings of the Di2 Sensor in the Garmin (on/off and change mode), and while on/off is fairly self explanatory, the second one is not!

    Basically, I have no idea what mode it is changing?!?!! Yes, the lights change when you change the mode, but always in an unexpected way (sometimes both flash, some times not, they never day flash).

    Any idea how to create pre set modes and cycle through those? I only want three: always on hi (for night), always on low (for group rides), and flash hi (for day).

  • NIce thank you for this review. I am really on the fence with these. Battery life is my main deterrent.

  • I purchased some of these lights and have been having a lot of issues with them and my Edge 820. I get ‘forming light network’ a lot, including during rides which results in the lights turning off. Often it seems to drop a light as well. Any tips for troubleshooting this?

  • I bought the taillight. It’s VERY dim compared to the previous model. I’m not sure I think cars would even see it in daylight.

    • Want to correct myself here. I talked to the local Trek rep and he showed me that if you hold down the power button for 8 seconds, it will go into "bright mode". MUCH better!

  • Do these light work with an Edge 510? I know the fancy control doesn't work (the downloadable app from Bontrager:, but all I'm after is on/off control when I turn the Edge on and off.

    When I try these lights with the 510, I can get them to pair...sometimes, but the pairing doesn't usually last through an Edge power cycle. When they do pair, they sometimes turn on/off with the Edge. It is rather frustrating that they "almost" work.

    In the comments there are people who seem to have gotten them to work with the 520. The 510 isn't that different.

  • I have noticed a dramatic drop in my Garmin 520 battery life after starting to use the Flare rear light. They are paired, i.e. I control the light through the computer, so I'm guessing that's the main issue. Has anyone noticed anything similar, and any tips if so? Thanks!

    • The dramatic drop in battery life happened only after I paired it with the light, so I'll try to run them without pairing. As for charging, I do use a wall charger, but I'll try to charge it using the computer and see how it goes. Thanks for the reply!

    • My Garmin 520 has been having the same battery life drain issue recently. I called Garmin and they spent a good deal of time with me, walked me through looking for corrupt files, uninstalling, reinstalling and other things. I asked if my lights being paired could be the problem and he seemed to think not. However, I decided to not use them paired and I did have better battery life. I also turned off the Bluetooth on my phone for one ride, to see if that would help. The Garmin guy said the worst thing for battery life is charging it through phone wall chargers, i.e. iPad or iPhone chargers, in my case. He said they slowly drain the battery life and that is not reversible. He recommends charging on the computer or using the approved Garmin wall chargers. My Garmin is three years old. Good luck!

  • I've paired it with my edge 130 and it doesn't seem to have the option to choose when the light starts (ie when the edge unit is turned on or when you start a a session). The Bontrager Connect IQ is not compatible with the edge 130 either. Any idea?

  • Big fan of your site.
    few questions, i just got a pair of these lights.
    Modes - I have the Bolt and didnt realize that the lights can only be controlled from a garmin device. Do you know if wahoo has plans to support lights? Or are there any other ways to control the light e.g. phone app? Manually cycling through the modes its still hard to distinguish whats what...

    Mounting - can i mount the light to the k-edge combo mount using the bontrager universal ion mount? It's just not very obvious to me.

  • Great article and I just picked up my set of these yesterday. I also added the bag clip for the rear light as putting it on my seatpost would be too hidden....even by my small seat bag. My saddle is not as high as yours.

    My question. I have a Garmin Edge 500 and realize that since that does not have bluetooth, I can't pair the lights with it (even though it has ANT and pairs with my Garmin Heart Monitor/strap). So, is it possible to control the lights with just a smartphone with bluetooth? I can't seem to find a way to do that even with the Garmin Connect app on my android phone..

    Thanks for the help and again, great article!

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