From the moment I first got my hands on the Ion Pro RT, the two of us were destined for a love/hate relationship. I've been night-riding for a long time, and (I think) I know what works best for me. Unfortunately, upon the first inspection the Ion Pro, many little red flags popped up, ensuring that the two of us would be off to a rocky start. Luckily, that didn't last for very long.

 

Bontrager Ion Pro RT

  • Output – 1300 lumens
  • Runtime Actual – 2.6 hours*
  • Price – $100
  • Modes – 1 Group: 1300 lumens, 800 lumens, 400 lumens, night flash 200 lumens, day flash 300 lumens
  • Recharge7 hours (no fast charging)
  • Water ResistanceIPX4
  • Light Weight – 183 grams
  • OtherConnect with Garmin® and Bontrager ANT+ devices. Sidelights for road visibility.

The Ion Pro offers a solid clamp that is a bit finicky, but won’t twist or move when properly installed.

Mounting

The Ion Pro uses a hinged clamp that is tightened together using a thumbscrew. Simple enough. The light itself attaches to the mount with a plastic rail, similar to an old-school cycling computer. Also simple enough. But while these two general mechanisms have been used for many years by a number of manufacturers, I've rarely found good executions of either, so I was skeptical of the Ion Pro at first.

Bontrager does offer a helmet mount for the Ion Pro, but it's of the variety that needs either a standard vented helmet or Bontrager’s Rally MIPS helmet with its magnetic and stylishly misspelled Blendr attachment. Luckily, there’s also a GoPro compatible mount cleverly disguised as a Blendr mount. It is $20 extra, but it does offer a world of mounting possibilities including other helmet mounting options and bar mounts. 

In the Wild

When it came time to slap the Ion Pro on the bars, I was grumbling internally and making bets to myself as to when I'd lose a part for the mount. To my surprise, the thumb screw has a stop in it that makes it impossible to lose, and is actually meaty enough to tighten with gloves. Once locked down, the clamp is incredibly solid, and doesn't twist at all, even under a hard landing.

The Ion Pro’s sidelights are bright enough to be seen, but not quite as bright as the Light and Motion Urban 1000.

That being said, there were two instances when I did not seat the thumb screw correctly, or seat the light completely on the rails, and the light fell off the bike onto the trail. Luckily, a 1300-lumen light is pretty easy to find in the dark, and confirms the Ion Pro can take a hard hit. It’s crucial to make sure the light and its mount are flush and parallel when sliding them together. And especially on 35-millimeter bars (which this clamp fits without the need to remove a shim or move a hinge), it takes some extra care to get the thumbscrew behind the notch that will keep it from dislodging. 

The Ion Pro is noticeably brighter than the Lezyne Power Drive 1100i, but there wasn't a significant brightness difference with the NiteRider Lumia 1200 Boost. That 100-lumen gain is there, but isn't going to make a difference out on the trail for most riders.

The Ion Pro has a warmer color tone, more similar to the Lezyne than the NiteRider. This isn't necessarily good or bad, more personal preference. The light-spread of the Ion Pro is more of the spot-light variety, but it does have enough feather to the sides to counter the worst tunnel-vision-syndrome.

If the clamp isn’t fully seated into the bottom of the light, the light will fall off. Luckily, it’s easy to find a 1300-lumen light at night.

Living with the Light

Mounting issues (and eventual non-issues) aside, one operation aspect really pushed my buttons. Instead of two groups of light modes, like every other light tested, the Ion Pro has everything in one group. It takes five clicks to cycle between the modes and is a bit like changing TV channels one at a time instead of just jumping directly to the one you want. It's hard to do while riding and switching to a strobe mode accidentally while in the dark forest leads to dance moves you don't want to do. But that’s where the ‘T’ in Ion Pro RT comes in. Transmitr is Bontrager’s other stylishly misspelled accessory that will control up to four lights with a handlebar-mounted button pad. You can use it to cycle between modes like you would using the light’s own button, but the Transmitr also offers the option to quickly switch from high beam to low and back. That benefit goes double if you’re running another Transmitr-compatible Bontrager light on your helmet, which you could control independently. The Transmitr goes for $40, which would bust the $100 ceiling we set, so I kept it stock. 

Luckily, the Ion Pro has a quality that makes up for its bare-bones button: battery life. Hands down, this Bontrager beats every other light in this test. Granted, the Lezyne 1100i has a port to plug in an external battery, so theoretically that light will last as long as you have new battery packs, but each one of those packs cost (and weigh) extra. As far as self-contained lights are concerned, the Ion Pro takes the whole cake. I got it to last for 2.6 hours on high, long past its 1.5-hour claimed lifespan. And as you near the bottom of that deep battery well, the Ion Pro’s power button changes from steady green to flashing green to flashing yellow to flashing red just after turning it on to give you an idea of how much time you’ve got left.

Despite some quirks, the Ion Pro was the brightest and longest-lasting light in the test, and that counts for a lot.

For whom does it shine brightest?

The Ion Pro and I may have our differences, but when push comes to shove and you need long-lasting, dependable light, the Ion Pro will answer the call. As long as you get the mount on properly, the light becomes an immovable barnacle on your bars, and its battery life is the best of the lights tested. I do wish the button layout were more trail-friendly, but if you can tolerate some extra cockpit clutter, the Transmitr button solves that nicely, and this light’s benefits are worth that extra expense.

This review is part of a four-part series of mountain bike lights under $100. If you missed the others, catch the link back to all the reviews here.