The Fenix PD31 flashlight is one of those rugged designs for the great outdoors that happens to double as a really useful bike light. Fuelled by two little three-volt batteries, it'll pump out an impressive 304 lumens in turbo setting for about two hours but an aftermarket Li-on rechargeable type would be my choice, if used with any regularity.
Speaking of which, it even incorporates reverse polarity protection should you accidentally install the cells incorrectly when trying to pitch a tent at 3am. Arguably, peripheral prowess could be improved but the neatly machined aluminium cowling gives a surprisingly good spread of useable light, especially in the highest modes.
Measuring a sensible 120mm long, the aircraft grade aluminium body feels every bit as tough as it looks and the black anodising is to a better standard than I've come to expect. Ours has retained its looks and proven genuinely water and shockproof which is particularly good news for expedition touring, camping and mountain biking. That said, inspect the little O- ring seal every so often and give the contacts a lick of Vaseline while you're there to lock the elements out and retain connectivity.
Complete with its own Cordura nylon pouch, the PD31 is extremely versatile- hung from a belt loop, or clipped conveniently to pockets for quick draws during roadside mechanicals and better still, the beefy nylon bracket with soft rubberised jaws mounts securely to a variety of surfaces including standard diameter fork blades and handlebars. Though sufficiently lightweight, our bracket proved incompatible with my helmet collection but Fenix offer plenty of helpful guidance on their website.
At the nerve centre we've a single, super bright CREE XP LED with a digitally regulated output. This might sound like a concept plucked straight out of Star Trek but spells and en to dimming/flickering-especially along twisting, rutted tracks. CREE quote a 50,000hour lifecycle, which is several years' hardcore commuting with expedition riding thrown in for good measure. Switches can be make or break for bikies and I had reservations about the squishy rubberised design located at its base. Thankfully, it demands a deliberate prod, so accidental engagements when lolling around in pockets or luggage should be few and very far between.
Surfing between settings is a matter of gently prodding the switch-fine for map reading, pannier rummaging and other stationary activities but something of an acquired art from the saddle! Turbo mode is best along unlit roads to around 25mph but guzzles batteries at a wallet worrying two and a quarter hours (2hrs 3 minutes actual using premium grade lithium types) whereas 124 lumens seems more appropriate (and economical) round town returning 7hrs 58 from the original batteries. Dipping down to 67 lumens is the most frugal and still delivers a very pure beam of light but we're talking contingency illumination and/or 12 mph along well-lit town centre cycle paths.
Great torch that doubles as a surprisingly powerful front light but get some aftermarket Li-on batteries if it's to be used regularly
road.cc test report
Make and model: Fenix PD31 Front Light
Size tested: Black
Tell us what the light is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
"The new Fenix PD31 is compatible with two CR123 or one Li-Ion 18650 rechargeable cell, giving excellent runtimes for those who prefer the economy and performance of rechargeable 18650 batteries.
Featuring a Cree XP-G LED with maximum output of 304 lumens, the PD30 has reverse polarity protection and is waterproof to IPX-8 standards.
· 304 lumens - 2 hour 15 minute runtime
· 124 lumens - 8 hour runtime
· 67 lumens - 16 hour runtime
· 2 lumens - 200 hour runtime
· Strobe and SOS mode
Sturdy, dependable high power torch that happens to double as a handy front light".
Tell us some more about the technical aspects of the light?
· Cree XP-G LED (R5) with a life span of 50,000 hours *
· Uses two 3V CR123A batteries or one 18650
· 120mm (Length) x24 mm (Diameter)
· 64.4-gram weight (excluding batteries)
· Reverse polarity protection
· Tail cap switch
· Capable of standing up securely on a flat surface to serve as a candle
· Made of durable aircraft-grade aluminum
· Premium Type III hard-anodized anti-abrasive finish
· Notice: The above-mentioned parameters (tested in lab using quality CR123A primary lithium batteries) are approximate and may vary between flashlights, batteries, and environments
Consumes dry cells alarmingly quickly so aftermarket li-on is best for regular use.
Tell us how the light performed overall when used for its designed purpose
The PD31 is a superb torch for generic outdoor duties that happens to perform very well as a contingency bike light. Build quality is superb, resisting everything the elements and accidental clumsiness could hurl at it, while output is remarkable given its diminutive stature.
Tell us what you particularly liked about the light
Pretty much everything (bar the run times) given the design brief.
Tell us what you particularly disliked about the light
Pesonally I like the option of being able to run both types of battery but would've paid a few pounds more for it to come equipped with a li-on battery.
Did you enjoy using the light? Yes
Would you consider buying the light? Quite possibly
Would you recommend the light to a friend? Yes, for mountain bikers and tourists seeking a torch that doubled as a powerful back up bike light.
About the tester
Age: 38 Height: 1m 81 Weight: 70 kilos
I usually ride: Rough Stuff Tourer Based around 4130 Univega mtb Frameset My best bike is: 1955 Holdsworth Road Path and several others including cross & traditional road
I've been riding for: Over 20 years I ride: Most days I would class myself as: Experienced
I regularly do the following types of riding: cyclo cross, commuting, touring, fixed/singlespeed, mtb,
Shaun Audane is a freelance writer/product tester with over twenty-eight years riding experience, the last twelve (120,000 miles) spent putting bikes and kit through their paces for a variety of publications. Previous generations of his family worked at manufacturing's sharp end, thus Shaun can weld, has a sound understanding of frame building practice and a preference for steel or titanium framesets.
Citing Richard Ballantine and an Au pair as his earliest cycling influences, he is presently writing a cycling book with particular focus upon women, families and disabled audiences (Having been a registered care manager and coached children at Herne Hill Velodrome in earlier careers)