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47g £24.96

The Kryptonite Avenue R-50 COB Rear Light is a powerful and competitively priced model with a decent blend of settings, catering for most scenarios. That said, most are comparatively thirsty, exhausting the lithium ion battery in five hours. This favours short-to-middle distance commuters and bike-as-car utility riders, rather than long-haul night owls

Kryptonite Avenue R-50 COB Light rear, cycle bike chip on board



As its name implies, the Avenue R-50 uses the increasingly mainstream COB (chips on board) technology, which makes better use of available space and ultimately, produces a more intense light. In this instance, we have 16 diodes, projected through a curved lens.

Peripheral bleed, courtesy of two fairly thin cut-outs, is better conceived than some and definitely not an afterthought. However, they’re not a patch on some dome types, such as Revolution Vision COB rear light, or Moon Gemini.

The composite shell feels solid enough and has resisted a couple of accidental ejections. Most notably when slipped into a jersey pocket too casually allowing a tumble onto a grassy verge.

Kryptonite don’t cite a weatherproof rating but suffice to say ours hasn’t missed a beat, subjected to heavy showers and of course, my garden hose torture test. Mind you, ensure the port cover is fully home when you’ve finished charging its lithium polymer cell, which we’re told will manage 1,000 charges before cashing in its chips.

Here at Seven Day Cyclist, we’re advocates of disciplined refuelling but we’re also realists. Forgotten to charge, been out longer than planned? Thankfully, the system defaults to the lowest setting, once the battery reserves hit 10%. 


A low profile, virtually flat switch incorporates a battery life/charge indicator. Green denoting fully juiced, red means you’ve hit the last 24%. Up to the job as a visual guide and, better still, when reserves tumble to 10%, an auto kick down defaults to the lowest setting. It’s fairly easy to locate and command wearing middleweight, full-finger winter gloves.


There are six modes. A sustained, two second press powers up, engaging high flash, the full 50 lumens, medium steady (25), then low steady (10). Then we have daytime pulse (50 lumens), night-time pulse (10 cascading upwards to 30) and finally, eco-flash.

A further, two second press powers down and sensibly, there’s a memory function, which defaults to the last choice. I’m yet to encounter any unintentional power-ups when it’s been bouncing around in my wedge pack, or pocket.


This is solid and generally well engineered, with the option of mounting vertically to clothing, or horizontally/vertically to the seat post via the time honoured “watch strap”. The strap achieves tenure to most the full zodiac of post diameters. Well, 31.8 to 25.4. With a bit of imagination, it can snake around frame tubes, too.

Kryptonite Avenue R-50 COB Rear Light cycle bicycle bike
Kryptonite, Avenue, R50, COB rear light bicycle cycle bike

Either way is very secure - perhaps overly so, in the context of my Passport wedge pack’s tab but I’d sooner that than one that launched mortar fashion come the first bump.



All settings are suitably extrovert. The full 50, though short-lived in steady is more than potent enough for fast, unlit roads. Admittedly, flashing is my default in these contexts but I tend to run two lights, one in steady, the other pulsing/flashing. Used as my only form of rear light, friends reckoned they could pick me out at 150 metres, 125 through town.


Compared with some, it’s not overly thirsty, good for 2hrs 12minutes (against 2hrs 15 cited) but in my book, 50lumens is far too intense for built up areas, especially in slower moving, congested/rush hour traffic. I’ve tended to alternate between daytime pulse, night-time pulse and eco-flash. Daytime pulse is also 50 lumens. There are brighter models, including Moon’s Gemini, numbers-wise, but the R50’s intensity is pretty impressive.

When asked, approaching riders reckon they could pick me out from 125metres along the open road and drivers appeared to acknowledge, slowing down at 50 metres or so, which was particularly tangible when negotiating roundabouts and generally entering the flow of traffic. Staying with this, it sat just the right side of assertive at close quarters, in slower moving queues. 

Kryptonite avenue rear light red bicycle cycle COB

Ours was generally tethered to my wedge pack, so directly at driver eye level. Even so, the setting’s pace was extrovert enough when post mounted, although positioning horizontally made best use of the side windows. This was much less significant, tethered to wedge packs, or clothing. 4hr 30 run times (4hrs 26, real world) are reasonable, giving enough bite for commuting to work, while retaining sufficient reserves to ride home after dark.


I’ve found ours slipping to economic flash on a couple of day rides - proves the failsafe works but in these contexts, I’d be inclined to pack another blinkie, just in case. Mind you, while ten lumens might not win any bragging rights, the COB technology gets the very best from them and, by my reckoning, it's superior to more traditional designs pumping out 15 or so and fully juiced, ours returned 11hrs 13minutes.

Talking of which, regardless of mode, I was initially perturbed by the speed at which the battery life indicator flicked to red. However, as the figures illustrate, this isn’t anything to worry about, so long as you’re not too lax when it comes to charging!  Night time pulse produces 10/30lumens and quickly became my default for dusk onward.


It starts at ten lumens, coursing upwards in a pulsing fashion to 30lumens and back to ten-very captivating. On a clear night, friends in cars stopped me at around 180 metres, through town, this dropped to 100 or so but the changing sequence seemed to make other traffic that bit more attentive. In keeping with the others, 5hours is pretty much your lot.

Medium and low steady are powerful, relative to their numbers and useful for those who like to run one light on a constant setting. I was pleased they featured a 25lumens mode - a nice compromise, not too bright for town but bold enough for the back roads. Provided of course, you’re happy being tethered to the 5hours.



Given the asking price, Kryptonite have come up with a relatively powerful, rugged rear light with a good spread of modes and reasonable run times. However, it does feel more limited, to shorter distance commuting, rather than longer nocturnal outings.

Provided you can tolerate the 5hour charge times, the Xeccon Mars 60 has grater peripheral punch and will run for almost 17hours - potentially a fortnight between recharging. Riders who like to let off some steam along the lanes may find themselves recharging the R-50 twice weekly, possibly more.


At the other extreme, while less powerful, Revolution Vision COB rear light  is half the price, offers 5 modes, superior side-on presence and a total output of 30lumens. It will also manage almost 40hours, fully charged in the flashing mode.

Verdict: 3.25/5 Bright rear light limited by peripheral punch and middling run times.

Michael Stenning



Ryton On Dunsmore

Coventry  CV8 3FH


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