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Infini Tron USB Rechargeable Rear Light
45g £34.99

The Infini Tron USB Rechargeable Rear Light caters well for most riding contexts, thanks to a spread of seven, broadly sensible modes, hybrid diodes and clever lens. Indeed, its brighter than numbers suggest in the lower modes, which is great for regular town riding. It’s more potent than I was expecting along unlit roads, too. However, run times in the highest flashing and constant settings limit its suitability for long, steady miles along the darkest lanes.

Pros: Solidly made, user friendly light, good choice of modes for general riding, practical run times in most settings.

Cons: Relatively short run times in highest constant and flashing modes, no auto kick-down, good, rather than great mounting kit.

bicycle cycling bicycle light rear back red


Measuring a relatively compact 26x24x53.5mm, The Infini Tron employs a 360-degree lens. The composite body feels reassuringly solid and although IPX4 (heavy rain) rating for weatherproofing is lower down the scale these days, it’s perfectly adequate for general road riding.

The snug-fitting USB port cover continues this narrative and so, unless riding in foul conditions sans mudguards (fenders for our US readers) I’d not feel inclined to give the port cover a precautionary lick of silicone grease.


Now behind the lens we have no less than 52 diodes-yes, 52. 42 Chips on Board (COB) as you’d expect for maximum, focused intensity and interestingly, 10 SMD (Surface Mounted Diodes), included to offer a broader, flood-type presence and theoretically, the best of all worlds. 

bicycle bike light rear red back

Both employ aluminium heatsinks to displace heat and foster long, productive lives. Infini have gone for a lithium polymer cell. This charges via the common or garden micro-USB cable, so shouldn’t pose any problems, should you lose the short, yet still adequate OEM unit.

Modes/Switch 3.5/5

We have 7. 2 steady- low and high (10 and 40 lumens respectively), 5 flashing (20,5, 5, 20 and of course, the 50-lumen daylight flashing). As we’ve come to expect, the Tron has a memory function, so you can just hop on, press the switch, then scoot off. Not that the single prods to go through the cycle are a hardship but saves time if you’ve stopped for a breather or are taking that familiar route home. A 1½ second press powers up and down. 

Aside from output, the patterns in flashing modes are different, so you can tailor to suit your environment, or in some cases, extend the run times. The switch itself is a rubbery, top mounted affair that is a cinch to find in pitch darkness and easily commanded in full-finger winter-weight gloves- on the move too, if you’ve mounted it on the seat stays. 

That said, you’ll be relieved to hear it’s not too responsive. A deliberate, sustained press is needed to turn it on off and you’re not going to be sweeping through modes at the slightest touch, either.

cycle bike bicycle rear red back light

Mount 3.25/5

Infini are catering for most contexts here. The body has an integrated clip for clothing, or luggage.


Then there’s the standard round (post), the aero counterpart, which caters for aero posts but crucially, seat stays, too. Finally, there’s a helmet option. I’ve had no issues with tubing diameters between 25.4 and 31.8 with the standard mount and the aero has entertained all but pencil thin seat stays. The composites feel a little whippy but with the paint-friendly rubber insert and beefy rubbery strap in situ, no issues in the real world.

bicycle cycle bike light bag loop rear

These days I tend to whip lights and brackets off when parking up in the street, but the light is easily removed and refitted with a deft twist. Cable ties are also supplied, primarily with helmet mounting in mind, but add security, assuming you weren’t porting it between bikes, or wanted to tether it to luggage. 

Run/Charge Times 3.5/5

These have been reassuringly faithful to those cited. Within a few minutes, during the test period and in temperatures between 4 and 14 degrees. Low steady (10 lumens) has consistently translated as 5hrs 54 (6 hours), high steady (40 lumens) 53 minutes (1 hour cited), flashing 1 (20 lumens) 8 hours 56 (9 hours official), flashing 2 (5 lumens) 13 hrs 27, Flashing 3 (5 lumens), 19hours 53 (20 cited), Flashing 4 (20 lumens) managed 3 hours 24 (3 hrs 30 cited) and the 50-lumen daylight, 7hrs 56 (8 hours).


Temperatures closer to zero may have a more pronounced effect, but for me at least, these have reassuringly accurate. On the charging front and using the short OEM micro-USB cable, 2hours 15 also seems bang on, when fuelling from a laptop/similar device. Zero to hero from the mains, under two hours, quicker still using an old tablet charge cable. Some folks deride the micro-USB, but when push comes to shove, their ubiquity ensures you can find, (or cadge one from a friend/colleague). Another, minor point is the Tron doesn’t have an auto kick down to the lowest mode, when battery reserves dwindle.

Output 3.5/5

In common with several others, I’ve tested in the relatively recent past, the Tron is brighter than the numbers might suggest and probably closest to Ravemen CL05 in these respects (I’ve had them running alongside each other for a couple of weeks). The 5 lumen flashing modes seem closer to those claiming 8/10 lumens and are arguably best for built up areas, although I have used them to “limp home” with when a more powerful light powered down unexpectedly.

Anecdotal evidence from approaching riders suggested they could spot the light from around 50, or 60 metres along the backroads, closer to 40 or 50 around town. The differing tempos and patterns mean you can tailor them to your environment, preventing it getting drowned out by competing illumination.


Talking of which, though I’d probably plump for the 10-lumen low constant, on group rides, the 5 lumen flashings are unlikely to upset anyone at close quarters. Peripheral presence is also reasonably good, thanks to the lens. I’ve never felt too stealthy, or off the radar when tackling roundabouts, or turning right. 

bicycle rear red light bike
bike bicycle bike rear red light

Beyond city limits and aside from limping home, the 20 lumen flashing modes rapidly became my defaults, given their blend of power to run-time. Brighter than I was expecting, they’ll certainly cut it along semi-rural roads-some riders reckoned they could spot these from 120-150 metres, although as my only source of rear light, when tackling miles of unlit country lanes and A-roads, the limitations became a little more obvious.

Unlikely to be a problem if you’re doing shorter sections or have found some while exploring but if the back end of beyond is your primary riding territory, I’d opt for something brighter and/or use the Tron as a secondary light. On a cheerier note, the 50-lumen day flash isn’t as potent as some, especially in harsh autumnal sun, but great when its overcast.

A straw poll suggests 250-300 metres, falling to 180 in strong sunlight. Of all the modes, I’m not sure whether the 40lumen constant was an inspired choice. Yes, its bright but will exhaust the battery within an hour. 


Given the lithium polymer cell’s capacity, something around the 20-25 lumen mark might’ve struck a better balance.

Durability/Weatherproofing 3.25/5

Despite some minor misgivings about the mounts, these seem to be holding up nicely and the light itself has shrugged at some torrential downpours, the odd direct hit from stray flints and small stones. I’ve left ours in situ while deep cleaning the bike, sloshing plenty of sudsy water its way- no issues whatsoever. The main thing (and this goes for rechargeable lights per se) is keep the light charged regularly and avoid habitually running the battery too low. Give the light a full charge at least 3 monthly (say if you’ve popped it into seasonal storage) to keep it healthy.

Value 3.25/5

£34.99 is competitive but there are several capable of giving the Tron a good run for your hard-earned. Ravemen CLO6 Sensored Rear Light  (The CLO5’s big brother) comes in at £31.99 boasts IPX6 weatherproofing, braking and a clever sensor function that increases the light’s intensity when it detects vehicle headlights. Run times and output also favour longer rides along unlit roads, although it doesn’t have an official daylight flash. BBB Signal Brake Auto Brake comes in at £36.99 and offers a braking function, 50 daylight flash and rider tuneable output and an auto kick-down, buying approximately 4 hours, should the battery come close to bottoming out.

Magicshine See Mee 200 is another very bright light that packs in a 200-lumen braking sensor and a tracer beam, for improved presence along the darkest roads, a 50-lumen day flash and smart sensors to choose the correct output. (£33.99) Size might be a deterrent for some but Lelumia the Beast  packs in a lot for £34.99 and is a better choice for long miles on very lonely unlit roads. A great bet for tagalongs and trailers too. However, it also lacks the Infini Tron’s charms around town. 


For the most part, Tron infini USB Rechargeable Rear Light is a reasonably capable all-rounder. Great for town riding, it offers plenty of presence, reasonable run times and the 20 lumen flashing modes are potent enough for unlit roads. If your commute, or training rides took you through town and country, it would be worth a closer look. However, the 40-lumen constant mode is of limited use and there are better options if most of your miles are along pitch black roads.

Verdict: 3.5/5 Decent light for all but the darkest roads and highest constant mode merits revision.

Michael Stenning – The UK’s largest cycle parts & accessories distributor




Ryton On Dunsmore

Coventry  CV8 3FH


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