Kryptonite Avenue R-50 COB

The Kryptonite Avenue R-50 COB is a bright, eye-catching rear light with some useful modes for making you conspicuous. Unfortunately, its mounting system means few bikes will be able to get the most out of its side visibility windows. With most modes having running times of five hours or less, its battery capacity leaves something to be desired too.

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The Avenue R-50 COB is a neat little unit, measuring approximately 8 x 3 x 2 cm. Behind the lens there is a series of surface-mounted LEDs. These are far smaller than traditional LEDs, meaning more can be packed into a given space.

In this case, I can report (after a painfully dazzling inspection) that there are 16 tiny bulbs, each capable of throwing out a considerable amount of light. Working together, they provide a bright and conspicuous light. At the ends of the body there are curved red screens, which allow the endmost bulbs to provide a considerable amount of side illumination – although these work better if the lamp is mounted horizontally rather than vertically (more on this below).

The specifications

This lamp has six modes, which you cycle through using the small, almost flush button on one of the long sides. Although flat, the button is tactile and I found I could work it wearing full-finger neoprene winter gloves, provided I looked at what I was doing. The button lights up green when the internal rechargeable battery is healthy and becomes red when you've less than 25 per cent juice remaining, which is handy for keeping tabs on the state of charge in day-to-day use. A longer press turns the unit on or off.

The modes available are a bright flash (50 lumens, 2:15 running time), a dimmer flash (10 lumens, 11:15 running time), a medium steady light (25 lumens, 2:15 running time), a low steady light (10 lumens, 5:00 running time), 'Daylite pulse' (50 lumens, 4:30 running time), and 'Nitelight pulse' (10 lumens pulsing up to 30, 5:00 running time). In testing, I found these running times to be close to what I attained. Such battery life numbers put the lamp towards the lower end of what I'd hope for from a rear lamp, with 5 hours or less on a full charge in all but the dimmest setting. In the brighter settings, which I'd imagine most people would want to use, those of us with long commutes could easily need to recharge this every day.

On the other hand, should you forget to charge the lamp, all is not lost. A neat feature of the Kryptonite unit is that, once the battery gets below 10%, the lamp drops automatically into its most economical mode rather than just die on you, like so many others. I really appreciated this touch when I ran low on power at night.

The modes are all impressively bright. If 10 lumens doesn't sound much, all I can say is that this lamp makes the most of every one of them, because even in its dimmest modes, the amount of light is impressive. The higher modes are very bright indeed. The output appears to be regulated, so that brightness doesn't drop off as the battery gets lower.

The two modes that really stand out are the Daylite pulse and Nitelite pulse. The former is a very strong light that brightens and dims about once per second. It's an eye-catching effect and likely to stand out in an urban scene. The Nitelite mode is a steady 10-lumen beam that briefly pulses to a much brighter light roughly every two seconds. This similarly seems to offer a light that might help you be seen in the street as it should help you appear distinct from all the other red lights on the road.

The lamp is charged through a micro USB socket on the back, covered by a decent rubber bung. With the rubber pulled back, the socket 'floats' in the middle of a very wide aperture with quite a lot of space around it. This means even chunky USB cables should be able to fit in. My first impression at seeing all the space around the port was that it would be vulnerable to being snapped should it get knocked when plugged in. But after plugging in a cable and applying a fair amount of force in several directions, I found no sign of weakness at all. Speaking of lack of weakness, the lamp also survived being dropped off my kitchen table onto a hard floor a couple of times.

The light is simple and effective in use. The button is clicky and tactile and the light levels are great. The lamp remembers your last mode after you turn it off and comes back on in the same mode, which is a useful touch.

Waterproofing seems fine, too; I used it in various spells of drizzle and rain, and it survived a more full-on test under my shower without batting an eyelid.

The mounting system

The lamp attaches by sliding a groove on the back of the lamp onto a rail on its mount. It comes with two mounts – one for attaching the lamp to a frame and one with a clip for attaching it to a bag or pocket.

The concern with the frame clamp is how it mounts the lamp to your bike. The mount is a small piece of shaped plastic that is held onto the bike using a stretchy rubber strap. Like most similar mounts, this has a curved face that fits around a tube on your bike. However, unlike some rival brands' mounts, this one is constructed in such a way that how you mount it to the bike determines the orientation of the lamp. If you strap it to a horizontal bar then the lamp will sit horizontally. If you strap it to a vertical bar the lamp has to sit vertically.

> Buyer's Guide: 14 of the best rear lights for cycling

If you look around, there aren't that many bikes with any horizontal mounting points available. Largely, this is limited to the subset of disc-brake bikes with bridges between the seatstays. In almost every case, then, you're going to fasten this lamp to a vertical bar, such as the seatpost or a seatstay. This is a shame, as the side visibility windows are at their brightest when viewed end on. If the lamp is mounted vertically – which it will be on almost every bike – then the side visibility windows throw a lot of their light where it isn't doing much good. When I mounted the lamp on my seatpost, for example, a lot of light was being thrown onto the underside of my saddle and the top of my tyre, rather than towards other road users.

That's not to say there is no side visibilty at all when the lamp is mounted vertically – it's actually not that bad. It's just that a little more care in designing the mount could easily have provided something that was more flexible and got the most out of the LEDs.

For the same money, Lezyne's KTV Pro Drive Rear 75 offers longer running times with its five modes, one of which is a brighter daytime flash of 75 lumens. Moon's Nebula costs another £15 but has a 100-lumen mode if you want more brightness (for just an hour), and also has longer run-times and multiple mounting options.

Verdict

The Kryptonite Avenue R-50 COB is a well-built, bright and conspicuous lamp for day or night rear visibility. The battery life is at the low end of what is acceptable, though. At 5 hours or less in all but the dimmest mode, it means somebody with a lengthy commute could be charging this as often as every day. The design of the mount also means that in most cases the lamp will be fastened to the bike in a way that doesn't get the most out of the side visibility windows.

Verdict

A good lamp let down by so-so battery life, and the mounting system could be more flexible