Bontrager Ion 350 RT front light

The Bontrager Ion 350 RT is an extremely compact light with a maximum output of 350 lumens and some neat features. In terms of output, its mix of spot and flood is very pure, with few imperfections, making it useful beyond city limits – although if you ride faster than 18mph or so then scanning for holes/similar hazards requires concentration.

What distinguishes it from the otherwise identical 350 R is its wireless transmitter technology, primarily designed with helmet use in mind. It works with a remote switch, so you can change settings without needing to move your hands from the handlebar when the light is helmet mounted. The Transmitr Remote is an aftermarket product (as used on the Transmitr Lighting Set reviewed last month), but the technology pushes the price up by a tenner, which, for me, is rather high for the level of performance relative to competitors.

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Starting with the basics, the bracket is a very neat rubberised watch strap design that offers secure tenure to the full zodiac of bar diameters and most standard road or trail-inspired commuter type lids. That said, fitting or removing it while wearing insulated winter gloves proved nigh-on impossible. In common with other designs, such as the Lezyne KTV2, you rotate the light 45 degrees, fasten the bracket, then whip the lamp round again. There's also a Blendr system of stem mounts, which keeps things clean.

Charging is quite lengthy – four hours when fully depleted – so having established run-times in each mode, I've been inclined to keep it topped up. The pronounced square power switch incorporates a battery life indicator, which changes from red to green when that 1450mAH lithium-ion cell is fully juiced. (Easily hidden, discreet office charging shouldn't be a problem.)

The indicator works the same way (but opposite) in use, although the lack of amber can lure you into a false sense of security. On our maiden outing, I was surprised to find it had suddenly slipped to red. Thankfully, there is a reasonable amount of grace and run-times are faithful to those quoted.

Build and output

The compact rectangular resin body is well made, and though IPX accreditation isn't mentioned, it seems well sealed from the elements. Heavy rain and sustained, provocative blasts from the garden hose have made zero impression to date.

A broad composite lens uses collimator technology and a decent reflector to get the very best from the single Cree diode. Bontrager claims visibility to other traffic is up to 1.5km – more about that in a minute.

The pronounced square switch cum battery life indicator sits slap bang in the middle and is reasonably easy to operate on the fly.

There are five modes in total: three steady, plus daylight and standard flashing, which should be enough for most needs. The highest is 350 lumens, prod again for 200 lumens, then 100 lumens. A memory function defaults to your last choice, which is always welcome.

Seeing by...

Real-world output is good. The flood does a decent job of road presence, while the spot provides a surprisingly sharp spot for riding by. Like others in this class, the highest setting is OK for semi-rural navigation to around 18mph, but much faster and it becomes harder to scan the road surface for holes, thorns, glass and similar hazards (other models, such as Moon's LX 360, have more navigational punch beyond city limits). Its 90-minute run-time also means this mode is better suited to shorter bursts.

Atop a helmet, it's a good companion for better quality bar-mounted main systems on the back lanes, useful for reading signposts and puncture repairs, and for occasional moderately paced trail work (600 lumens is my helmet light benchmark for speedy nocturnal singletrack stuff).

Stair-casing down to 200 lumens strikes the best balance between output and economy (2hrs 57mins from a full charge), and has been my default for suburban contexts. Spotting holes and hazards proved easy enough to around 23mph, which is about as fast as I like to push things in built-up areas in any case.

Being seen by...

Rather like the Electron F-150 and F-400 lights, Bontrager has opted for amber side windows. These are more effective for peripheral presence than I was expecting, and compared with the two Electrons.

In the higher constant settings, the relatively broad cloak of light helps – all things being equal, I've never felt unduly invisible when entering the flow of traffic, or negotiating roundabouts.

Helmet or handlebar-mounted, with the full 350 on tap, visibility ranges from 300m on clear nights to 125m on murky ones, and even in moderate fog you'll stand a sporting chance of being spotted from 200m or so. Through suburban stretches, given competing illumination, other traffic took note from 125m.

On the 200-lumen setting, I seemed to register with other traffic to around 100m.

> Buyer's Guide: The best front lights for cycling

Predictably, flashing was far more impressive: 700m tops along the open road on a starry night – excellent, but a way off the 1.5km cited. Flashing's pace means it also holds its own through town – 300m on a clear night, with those amber windows coming into play.

Night flash run-times have been a consistent 8:53 – 7 minutes short of the 9 hours claimed, but perfectly acceptable allowing for the factory battery clause.

Day flash returns almost an hour more and is easily one of the best of its kind, at least in this class of light.

Subjectively, I liked the Ion's versatility, small dimensions and that brilliant day flash. Objectively, £55 is relatively expensive for this level of specification. I've seen Blackburn's Central 700 and the Moon LX760 offered for similar money online.

Verdict

Some nice features, especially the day flash, though a bit expensive given the overall specification