Issue #017 Review

Bontrager Ion Pro RT and Flare RT light set review

With the Ion Pro RT front light and Flare RT rear light, Bontrager put a particular focus on daytime usage. The promise: visibility up to a distance of 2 km in both directions. We subjected them to demanding winter testing and tell you what we think.

With its maximum output of 1,300 Lumen, the Ion Pro RT front light leaves much of the competition behind in terms of brightness, like, for example, the Sinewave Beacon that we tested in the last issue. The light isn’t just very bright but also throws its beam evenly and sensibly on the road or trail. The beam is focussed at the middle but spreads enough light to the sides to illuminate the full width of the path you’re on. With a perfectly round beam, you have the option to mount the light upside down or rotated. Thanks to small cutouts it can also be seen from the sides. That said, they could happily be a little larger! Both the headlight and its counterpart on the rear leave a high-quality impression and feel as though they could take some abuse. However, riders in Germany should note that the Bontrager light set is not StVZO approved. Make sure to check your local laws before buying and using them!

Bontrager promise a run time of 1.5 to 6 hours in the three continuous modes (1,300/800/400 Lumen). Our testing found that might even be a bit longer, despite frosty conditions. In the flashing daytime running mode (max. 300 lumens) the run time is quoted as 22 hours, while in the pulsing night mode (max. 200 lumens) that’s claimed to increase to 26 hours. However, something we did miss is a continuous low beam. Even the weakest constant option with its 400-lumen output is still very bright and quickly draws the ire of other road users. The irregular pulsing of night mode is great for being noticed by others, but sometimes constant illumination would be more appropriate.

The Flare RT rear light offers between 4.5 hours run time in its constant daytime running mode (25 lumens) and 15 hours in the pulsing night mode (5 lumens). In addition, it offers two flashing daytime modes outputting 90 and 45 lumens, which offer 6 and 12 hour run times respectively. A further constant night time mode puts out 5 lumens – that’s exactly the kind of setting we missed on the front light! Quoted run times don’t even include the 30-minute emergency capacity that throttles the brightness of the light when the battery is low in the hope that you’ll still make it home safely.

If you always use the same mode you can lock the one currently in use by holding down the light’s power button for 8 seconds, thereby avoiding accidental changes. A small detail that is not to be dismissed is that the lights remember the last mode they were in, which can save a lot of clicking with the multitude of options on offer. We also really appreciated the fact that the rear light can automatically adjust to the ambient light level and switch to the suitable day or night mode automatically. That’s not just helpful when riding into dusk but also offers a boost in safety when entering spaces like tunnels where you need a boost in visibility. However, by default, this functionality is turned off. You can activate it by holding down the power button for 8 seconds with the light turned off.

What we didn’t like quite so much were the mounts. Once the lights are fitted, they sit securely, but the lever to release them is small and hard to use, presenting a particular challenge when wearing gloves. It’s also a pity that the provided mount for the front light doesn’t provide any option to adjust the rotation of the light. Depending on the shape of your bars, its orientation could become an issue. However, Bontrager offer a separate adjustable mount for € 10. A clever detail of the rear mount is that it is angled at 16 degrees. That means the light sits vertical to the ground making it clearly visible when mounted to the seat tube or seatpost.

Both lights offer Bluetooth and ANT+ connectivity, allowing them to be connected to the Bontrager Transmitr remote and compatible Garmin Edge bike computers, where you can choose the mode and check the battery level. However, we can’t help but feel it would have been possible to get a lot more functionality out of the wireless connection! For example, we would have liked to see the option to individualise modes, which would have allowed us to configure the constant night riding mode we wanted ourselves.

If you’re looking for daytime running lights this set from Bontrager will be a trustworthy companion. The Ion Pro RT front light and the Flare RT rear light convinced us with their sturdy, high-quality build, good light output and lots of smart features like the automatic brightness adjustment and wireless connectivity. The run times are also quite impressive! The overall impression is only clouded by the hard-to-use mount and the lack of traffic-legality in some countries.


  • up to 1,300 Lumen output with lots of sensible modes
  • visible up to 2 km
  • Pleasantly shaped light beam with great illumination
  • sturdy, high-quality build
  • automatic brightness adjustment of rear light


  • automatic brightness adjustment only on rear light
  • mounts don't match the refinement of the lights themselves
  • potential of wireless connectivity not fully made use of
  • not road legal in some countries

Tester: Robin Wormer
Duration: 3 months
Price: € 169.99
Weight: Front: 178 g, Rear: 33 g (with included mounts)
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Words: Photos: Phillip Schwab