SEVEN DAY CYCLIST
CYCLING, BUT NOT USUALLY RACING
LATEST UPDATE: MAY 30th
OXFORD ULTRATORCH R75 REAR LIGHT
The Oxford Ultratorch R75 Rear Light is the marque’s most powerful to date, pumping out a maximum of 75 lumens. However, runtimes are modest so it’s arguably a better choice for deskbound commuting/winter training, than Audax, or similar endurance riding (unless you’re planning on re-fueling it from a USB dynamo). That said, it charges relatively quickly, from the mains and Oxford have turned the build quality up a notch, or two.
Pros: Excellent output, relatively quick charging.
Cons: Basic charge life indicator, modest battery life by contemporary standards.
Behind the PMMA collimator lens sit 24 COB diodes. It’s fueled by a rechargeable 18650 (3.7V 700mAh) lithium polymer cell, reckoned good for 500 charge cycles. Promises a few years faithful service, before becoming bin-fodder. Good charging habits (avoiding regular discharge, charging halfway before putting into seasonal hibernation etc) also helps matters.
Compliance with IP65 means it’s completely sealed against dust, and will withstand jets of low-pressure water, at close range. In practical terms, good enough for foul British winters, but ensure the charger-plug is fully seated and avoid full submersion. I’ve unintentionally dropped ours on a couple of occasions, with no obvious signs of damage, which is similarly reassuring.
The switch is an easily located, centre mounted oval shaped affair, with a distinctly rubbery texture. Ours felt less positive than some but wasn’t difficult to command wearing winter-weight gloves. Neither have there been any issues with it powering up, when holidaying in pockets, or bike mounted luggage.
There are officially four modes in total. Three steady and one flashing but I discovered a fifth, pulsing option. A firm double press brings the light alive, subsequent presses will scroll from steady (high (75 lumens), medium (40 lumens) and low (25 lumens) to the very distinctive 25 lumen flashing and pulsing counterparts. A memory function would’ve been super convenient but wasn’t a deal-breaker for me.
A tiny charge indicator window glows blue, flashing red when reserves dip to 15-20% In the real world, I’ve managed about 40-45minutes. Assuming you’re not already in flashing/pulsing, this gives the option of nudging down to conserve power. Ignored, the indicator will flash furiously, signaling imminent power-down.
The light bolts to a Go-Pro type mount, permitting it to cadge a lift on some saddles using a compatible interface. Otherwise, it tethers via the familiar crescent shaped bracket and the light’s angle adjusted using a 10mm spanner.
This features an integral paint/finish friendly insert (solves the problem of them going AWOL) and “ladder” type strap. I’ve had no issues with post diameters between 25.4 and 27.2, or indeed seat stays.
Even the pencil thin type, typical of classic road framesets. The strap feels sturdier than it looks, although its easily substituted for the ubiquitous doughnut type, should you be unlucky enough to break, or lose the original.
Charge Times 3.5/5
From the mains, when completely depleted it will charge in 2.5 hours, add another 20 minutes from a PC/Laptop, or similar third party device. Convenient enough for most office scenarios. Less convenient is the charge port pattern. Not the common or garden micro- USB, which rules out borrowing one.
Dynamos vary - I've tended to top ours up on a long day ride (5 hours plus) then, pop it into a power bank, or back into the mains, depending on contexts.
This winter has been decidedly wet, which has been perfect for assessing weatherproof characteristics, generally. Lights and lubes, in particular. The R75 has primarily been seat stay mounted and hasn’t missed a beat.
Regularly engulfed in a tsunami of scuzzy, standing water and muddy spatter, there’s been no evidence of ingress. I’ve not felt inclined to give the port cover a lick of silicone grease, either. Same story when I’ve left it in situ, while giving filthy bikes sudsy bucket washes, then rising with the garden hose.
Output is impressive in all the settings. Flashing tends to be my default and while less impressive than tuneable designs including, Knog Cobber Mid Rear Light friends reckoned they could spot me at 180 metres along pitch black lanes. 220 on a really clear night, dipping to around 125 through patchy fog.
Talking of which, it’s not a daylight mode in the bright sunny day sense but certainly stands out in gloomy January afternoons, something I partly attribute to the collimator lens. The sequencing tempo is also pretty distinctive.
No problems with stealth at roundabouts, junctions and generally entering the flow of traffic. Round town, its great at dusk, yet not too intense for congested rush hour crawls. There’s not much in it, but used as my only form of rear lighting, pulsing has a very slight edge over flashing along semi-rural and unlit roads. The tempo dulls to a low, constant glow but never completely out, which I found psychologically reassuring. Again, in terms of visibility, we’re talking 150 metres at a conservative estimate.
The R75’s lowest steady has been my default, for group outings. Anecdotally, others reckoned they could pick it out at 120 metres along dark lanes and 80odd, through sub/urban stretches.
The medium constant setting strikes a good balance between output and economy. We reckon its visible to around 120-150metres. In similar contexts, it’s had the edge over Xeccon Mars 60 COB Rear Light although this levels out, in terms of output when decelerating.
The High Constant is very useful for shorter rides along pitch black/foggy roads, it will also double as a surprisingly effective daylight running mode, on sunny days. On balance, we reckon 180 metres on a very dark and rainy night. I certainly wouldn’t want to be following it for long (nor did approaching vehicles!) Predictably, it’s also the least frugal.
Run times 2.5/5
I was pleased to discover these were generally faithful to those cited. Almost the full 6 hours in flashing (5hrs 56) low Constant (3 hrs 54, 4 cited), Medium constant 2hrs 55 (3 official) and high constant (1hr 58, 2 official). Curiously, pulsing has only returned 5hrs 30, from a full charge.
Even allowing for the higher outputs, battery life is decidedly modest by contemporary standards. For example, its R50 cousin will run close to 44 hours, in some of its flashing settings. These factors tend to root the R75 to middle distance commutes, training and TTs, rather than Audax, or similar endurance events.
There is quite a lot of choice at this end of the market. Xeccon Moon 60 COB rear light comes in at £28.99. It’s not 60 lumens in the literal sense, but the intensity when decelerating and much longer run to charge ratios may swing some wallets.
Kryptonite Avenue R-50 COB Rear Light is a closer comparator, although lacks the R75’s peripheral punch, which can make all the difference, if you’re going the single rear light route.
I’ve warmed to the R75. Quality of output is excellent and modes cater for built up and rural contexts equally well. Quick charge times and decent build quality are also definite plusses. However, there are a wealth of bright lights offering more generous run times.
Verdict: 3.25/5 Powerful and solidly made but modest run times.
PUBLISHED FEBRUARY 2020
BUILDER OF STEEL CYCLE FRAMES
Ryton On Dunsmore
Coventry CV8 3FH