Cyclingnews Verdict

Several seasons in, Bontrager’s neat, powerful and wirelessly communicative, controllable and accessory-rich Ion Pro RT still sets a benchmark for compact on- or off-road bike lighting

Pros

+
Impressive reach with reasonable spread
+
No sharp edges or beam oddities
+
Warm, eye-friendly beam colour
+
Mid and low power settings are still usable
+
Fits all round bars as standard
+
Multiple aftermarket mount options
+
Daylight flash and side visibility
+
Safety catch switch
+
Wireless remote, rear light and Garmin connectivity
+
Proven reliability

Cons

-
No Bluetooth
-
Slow recharge
-
Not fully submersible in theory

You can trust Cyclingnews Our experts spend countless hours testing cycling tech and will always share honest, unbiased advice to help you choose. Find out more about how we test.

Since its launch back in 2018, Bontrager’s Ion Pro has been a go-to light choice for many. In every buyer’s guide to the best bike lights, you’ll find it listed, so what makes it so good? We’ve been putting the powerful 1,300-lumen light to the test, just in time for the onset of autumn. Read on to find out whether it’s still worth your hard-earned cash.

Design and aesthetics

Bontrager’s Ion Pro RT looks relatively simple, with a rectangular casing housing the 4,800mAh battery and single recessed LED. Two orange side lights give traffic awareness without spilling light in a distracting way, and the raised rubber power button is relatively easy to find even in thick winter gloves. The double click start stops accidental ignition if you chuck it in a bag or pocket, too.

The light comes with a hard, round mount that has an integral rubber gripper so there’s no worry about it getting lost or flopping about when you’re trying to fit. There’s enough adjustment on the threaded rod and a long, easy grip-tightening knob to fit any bar from 25.4 to 35mm, too. The light can be installed or removed easily with a quick-release catch if you want to take it away without disturbing the mount. Alternatively, you can slot it onto a strap-on helmet mount (£19.99), GoPro-style ‘out front’ mount in either a road (flat) or MTB (kinked) version instead (£12.99) or take the sliding shoe off and fit a direct GoPro-style mount (£4.99). That’s not where the Ion accessories stop either, as Bontrager also makes an ANT+ driven Transmitr remote that can control the Ion and Flare RT rear light.

While the wireless smarts are handy, the basic performance of the light is the key thing and Bontrager has aced it here, too. The beam is impressively punchy in terms of reach but there’s still enough peripheral to give you terrain context off-road or some ‘look round’ on upcoming corners on the road. Unlike some multi-LED lights, there are no distracting ‘steps’ or overlaps in the beam and a soft edge doesn’t cause peripheral distraction either. The warm colour temperature of the LED also reduces dazzle in damp conditions and overall retina strain compared to harsher blue-white hues. The upshot is a light that lets you ride without compromise on roads you know, and even if you’re hitting up brand new routes, you don’t have to throttle back much.

There’s plenty of juice in the battery for a full cold-conditions power hour with plenty in reserve just in case (even on our well-used sample from last year). The medium 800-lumen constant mode is still powerful enough for a decent pace and even the 400-lumen low mode can be used in lit areas on slow, simple surface climbs. The toggle through the night and day flash modes isn’t ideal when you’re trying to get to full power for an upcoming descent, but they obviously improve versatility and safety in traffic. Being able to toggle modes through the Bontrager Transmitr MicroRemote or a Garmin head unit gives you a workaround though. You can also get more accurate battery level info through your Garmin, which is great as the colour change button alerts still leave a lot of guesswork if you’re not clock-watching diligently. If Bontrager could add Bluetooth connectivity to open up more devices, including smartphones, that would be a great addition.

Despite the smarts and a relatively low IPX4 water resistance rating, we’ve had no issues with reliability on several Ion lights that we’ve run in all weathers. It does take a long time to recharge with a standard USB connection though, so get it plugged in as soon as you’ve finished riding if you’re forgetful. If you don’t want a wireless connection, then the 1,000 lumen Ion Elite R is £79.99 and the 700 lumen Ion Comp is £64.99.

Bontrager’s Ion Pro RT is a really powerful but compact light that lets you night ride with very little compromise, and it’s got the battery capacity to back it up. It’ll fit any round bar securely as standard, but comes with a lot of different mount options as extras. Wireless connectivity boosts convenience and control, it’s got proven reliability, a safety catch switch, and it’s a great price for the level of performance and tech you get. If we could get Bluetooth comms and/or more detailed run time info, we’d be giving it a five, but it’s still a category benchmark whether you ride on- or off-road.