Electron Terra 3 front light

Putting its cards on the table from the outset, the Electron Terra 3 front light is described as an off-road light. The previous range-topper, the Terra 2, is still available and - confusingly - is a rather different beast with a separate battery pack and two individual light units. On test here, the Terra 3, an all-in-one light with three Cree XP-G R5 LEDs giving a claimed 800 lumens on high-power.

As any fool knows, or at least road.cc readers, light manufacturers have been known to use lumens somewhat hyperbolically, and you can go to ebay and find some pretty outlandish claimed outputs (such as a 5000 lumen light for £32!) Our comparative testing gives rather more useful information - see the beam-o-tron comparatorator at the bottom of this review.

On full power, the Terra 3 kicks out a more-than-useful 1340 Lux at 2 metres, with a particularly widely-spread beam. Off-road, this wide beam is superb, giving a wide field of vision that enables you to make rapid progress without fear of overhanging branches or other obstacles lurking in the gloom.

For road use it provides plenty of illumination but the wide beam makes it awkward to find a position that doesn't dazzle other road-users while still lighting far enough down the road. We ended up using it a bit like full-beam on a car: switching to full power for fast sections of road and then hastily dropping to a lower setting when someone came around the corner. Here a narrower beam would probably be better.

Electron note that, like all of their lights, the Terra 3 is not BS-approved (for cost reasons they say, but we couldn't imagine a helmet-manufacturer applying the same logic). It lacks any side-illumination which is a requirement for bicycle lights intended for road use. It's a shame that the slight recesses on each side of the bezel (see picture) weren't a bit deeper so they could let some useful side illumination out - they appear to be merely cosmetic.

So far so good then. It's a neat package and kicks out plenty of light, albeit with a beam width better suited to off-roading (not unreasonably, given it's marketed as such.)

However, we found that there is rather a weak-point to the Terra 3 - the mounting bracket. Our first impressions of this were good too - it has a neat clamp with an easy quick-release function (you partially unscrew the screw and then it pivots out of the way allowing removal of the light). On our first test ride, an over-the-bars incident on some wet rocks at Afan saw it snap clean off. But even that, we liked. It's a big ask to make a bracket that can stand up getting smashed against some rocks, but it snapped in a way that allowed the light to be slotted back onto the bracket and zip-tied in place - a limp-home mode if you like.

The part that broke is a plastic piece that fixes between the light body and the bar-clamp (see picture). "Clever," we thought, "a cheap bit breaks and you don't damage the expensive bits". The distributor sent us a replacement bracket, but when that failed again a few rides later, this time with no crashes, we began to have some doubts about how clever it really was. The second time around, the little screw that holds the plastic bracket to the bar clamp stripped out the threads in the plastic, leading to a wobbly light and then no light.

Quite simply, the plastic part needs to be made of something tougher than plastic. A 250g lamp-unit held in place with a tiny self-tapping screw into an awfully slender piece of soft plastic is no recipe for durability. When we asked Electron about this, they said they'd had only one unit fail in a similar way, despite extensive testing and racing with these lights.

Maybe we were unlucky, but the fact is that this is a high-stress part. With no pivot between the clamp and the light, if you decide mid-ride that you want to adjust the angle of the light and can't be bothered to loosen the clamp (likely, as the screw gets really fiddly with gloves or cold hands), you'll break it sooner or later.

It is far from the first time we've seen a really decent light where money has clearly been spent optimising beam output, battery life and so on, but where the clamp appears to be an afterthought. In this instance, replacing a small plastic part with an aluminium one costing a couple of quid more would solve the problem.

One of the brackets that broke was apparently a pre-production part, and Electron tell us they are planning a better CNC'd metal clamp, but that this is still a few months off.

Another minor niggle (again, common to plenty of lights) is the lack of peak on the lamp unit. As the Terra 3 is set a bit further forward relative to the handlebar than many lights, this is a bit less of a problem here, but it would prevent you getting blinded when you're out of the saddle and hunched over the bars.

User operation of the light is dead simple, and - for those who don't read instructions - Electron include a simple key on the back of the light. Two clicks to turn on, one click to toggle through the 3 modes, one looooong press to turn off. Really long. We timed it at three seconds, and this seemed unnecessary. We're talking minor details here, but surely one second is enough? If you're an irritable sort of person, this kind of thing can bug you every time you use something.

The three available modes are high power, medium and low power. There are no flashing modes (flashing lights are not much use off-road). We were very pleased to discover that unlike some other lights, we could install the Terra right next to a (Cateye) wireless cycle computer without any interference.

The power button changes colour to show you how much juice is left, starting at green and then going amber and finally red. On high power, with a claimed life of 3 hours, we were surprised to see that the indicator had turned red at 1h40, but the light was still going strong at 3h15. When the battery is nearly gone, the light drops to low power so as to give you the best chance of getting home.

You might well be able to justify owning a mountain bike and a road bike, but if you're investing in a good light you probably want it to be able to handle off-roading and on-road use.

This is an excellent off-road light - you can see enough to ride unfamiliar trails at a decent pace. The wide beam-angle shows up what's coming up even if you're not yet pointing at it, and even lights up overhead obstacles (good for avoiding low branches).

As a road light it is a bit less well-suited. The beam is so wide that it's hard to choose an angle and power-setting that lights far enough ahead for speeds above 25mph without dazzling everyone in sight. We'd want better visibility from the side to use this on road, too.

The Electron Terra 3 has an enviable combination of compactness, low weight, decent battery life and a blazing output. A tougher bracket would put this near the top of the list if you're looking for an off-road light.

If you want a light that can do everything on-road and off-road, you may find better options elsewhere - but you may also have to pay more for them.

Verdict

Good, compact off-road light - but we weren't impressed by the mounting bracket.