Gaciron W12BR-200 Smart Brake Warning Bicycle Shelf Braking Light

The Gaciron W12BR-200 Smart Brake Warning Bicycle Shelf Braking Light is solid, waterproof and very bright and comes in at a very modest price. In addition to its 200 lumen maximum output there are modes suitable for most riding situations, and the running time is very good. My only concern is the slightly restrictive, plasticky mount. Yes, it's functional enough but it does feel decidedly low rent.

> Buy now: Gaciron W12BR-200 Smart Brake Warning Bicycle Shelf Braking Light for £22.15 from Gaciron

The light has a slightly old-fashioned look and feel, due in part to the twin diodes and integrated reflectors, which are designed to reflect light from other vehicles' lights.

The unit, though quite large at 100 x 31 x 32mmm isn't unduly weighty and feels reassuringly solid – more so than it looks might suggest. The lens has a large surface area and is claimed to illuminate in a 300-degree arc.

It has an impressive IPX6 resistance to the elements, which means it can survive high-pressure water spray from any angle. There's a generous switch-cum-battery charge indicator and a well-sealed USB-C port.

It's powered by a reassuringly powerful 1200mAh lithium-ion battery. Braking function aside, there are five modes, two steady and three flashing. The steady two, at five and 15 lumens, may sound a little underpowered on paper but that didn't feel the case in practice.

There's also a 200-lumen 'fog', a 15-lumen fast flash and a 5-lumen low-and-slow flash; the braking function output is 60 lumens.

This works using a decelerometer, which is the same system other bike braking lights use. Strictly speaking, it's a slowing sensor that will sense a drop in your pace and trigger the 60-lumen light for three seconds. There's a stop-start function which, as the name suggests, detects whether the bike is stationary, or moving, turning it on, or off to conserve battery.

This seems to be 'hard wired' and you can't overwrite it, but I've not found this problematic. Stop for two minutes, it'll turn itself off and seems to re-engage within a few pedal strokes. Useful for rest stops, or if you're a little forgetful.

Mount

The light comes with two mounting options – one for saddle rails, the other for a rack. This might be a little limiting for some, as I tend to use seatstays or luggage loops. Given I use bigger wedge packs and SQR luggage, saddle rail mounts are of little use to me.

However, I found that with the power of the mighty zip tie, I could mount it to a trailer, including one with box-section tubing. And with a little perseverance I was even able to attach it to my ancient SQR Tour bag.

I fitted ours to a Topeak rack and I found the mount reliable, with no rattling over lumpy lanes, railway crossings and bridlepaths.

Switch

The switch's location is convenient and easy to locate and operate even with weighty full-finger gloves. A three-quarter second press turns the light on and off and the memory function ensures it starts in your last mode, while a single firm push will cycle through the modes

I was pleased to discover you can disengate the braking function by selecting any mode and depressing the switch for three seconds, when it will flash for three seconds to confirm the choice. The same process will turn the braking function back on again.

Output

I found the light's output brighter than the numbers would suggest. Okay, save for a bail out, the steady 5-lumen setting wouldn't be my first choice for unlit backroads but it still has sufficient punch for a shared-use path and to some extent in well-lit town centres – especially with the braking function activated.

In practice I tended to use the 5-lumen slow flash or 15-lumen steady. Other road users seemed to take note at about 20 metres, or further back when riding on unlit roads. And for this reason I reckon it's a good call for group rides, where it's bright but not retina-burning. Though do turn the braking function off...

Fellow cyclists said they could spot the 15-lumen output at around 40 metres even at dusk, the tempo halping it to be quite noticeable.

I used the braking function to maximise visibility at roundabouts and during stop-start traffic. I also feel that mounting it vertically on a rack or trailer arguably gives the peripheral punch a further boost.

In the countryside a farming friend reckoned he could pick me out at 75 metres – or at more than 180 metres with the 60-lumen braking function engaged.

The 200-lumen fog mode certainly cuts it as a daylight running light. It's powerful and the tempo is striking, with a neighbour commenting he could see me from 500 metres away after dark, and I reckon Gaciron's claimed 1,000m visibility isn't that far from the mark.

Run & Charge Times

Life's not long enough to check the claimed 100 hours in the flashing 5-lumen mode – but it's still going strong, with no hint of the red charge light indicator. With the braking function deactivated I returned runtimes within a few minutes of the times claimed.

The high steady mode gave me 17 hours 15 minutes compared with the 18 hours claimed; the 15-lumen quick flash 61 hours 54 mins (62 claimed); the 200-lumen fog mode gave me 9 hours 55 (10 hours). These were recorded in temperatures from 4-13°C and runtimes would go down in lower temperatures. Braking will inevitably also have some impact but it's difficult to pinpoint how much and will vary with how many hills you tackle and the amount of stop-go traffic you ride in.

Charging is pleasingly quick, going from pancake flat to fully juiced within the claimed 90 minutes, especially when using the mains. A lithium-Ion battery will have the best chance of a long life if you charge it frequently, and given its rapid charging speed, this shouldn't be a hardship.

Finally, if you're putting your bike or light into storage, make sure you charge it at least every three months.

Durability

Ours arrived during a very wet and wild spell and the light lived up to its IPX6 rating with no kinks in the armour. I'd still be inclined to add a precautionary slither of silicone grease to the charge port cover but I've had no issues to date. The occasional hit from stones have had no effect and caused no scratches.

How well the mount will fare in the long-term remains to be seen but again, there have been no isses so far.

Value

Its £22.15 RRP is extremely hard to argue with given its spec, and for that I'll forgive the slightly underwhelming bracket.

The Cateye Viz 100 costs £24.99 and only puts out a maximum 100 lumens. It also only has IPX4 weatherproofing, there's no braking function and the mount could be better.

I remain a huge fan of Topeak Mega Rear Light which comes in at £24.99. It's been around a good while, visible to 850 metres and is extremely frugal. Its AAA cells now look a little old-school but replacements are readily available.

The Magicshine SeeMee 180 Bike Taillight V2 costs £29.99 and has a 180-lumen braking function and features an ambient light sensor, which adjusts its output to ambient lighting conditions, theoretically maximising runtimes and without dazzling other traffic. I was impressed with its predecessor, though the braking function did put a dent in runtimes.

For further favourites check out our best rear bike lights buyer's guide and our best bike lights buyer's guide for a wide range of lighting options.

Conclusion

I've been impressed by the Gaciron W12BR-200 Smart Brake Warning Bicycle Shelf Braking Light. It's powerful, versatile enough for most types of riding, it's quick to charge and generally well made – though I'd have preferred a better, more versatile mount.

Verdict

Solid, bright and waterproof light with good modes and a handy braking function, though the mount could be better

> Buy now: Gaciron W12BR-200 Smart Brake Warning Bicycle Shelf Braking Light for £22.15 from Gaciron