The Fenix TK15 is the big brother of the PD31's I reviewed recently and offers the same standards of construction but with considerably greater oomph.
Another general-purpose lamp that doesn't fall into the jack-of-all-trades, master of none category, 337 lumens is genuinely impressive (albeit not as powerful as some ultra bright bike specific rechargeable systems) but the switch on mine seemed prone to accidental engagement and the otherwise sturdy nylon bracket works best on stems with rises between zero and ten degrees.
Too cocky for my own good, I suspected a rival brands' li-on battery would fit - it didn't lodging immovably in the body. Five minutes sustained but considered blows from a rubber mallet followed to shake it free and I'm pleased to report the TK15 survived completely unscathed. On some levels this shouldn't come as a surprise since it's built from machined aircraft grade aluminium, employs the same CREE LED and complies with IPX8 standards of shock and water repellency so should take vibration and everyday casual neglect in its stride. As it passed my hosepipe test easily, I went one stage further, leaving it immersed in a metre of salt water for 20 minutes hitting the switch; we were ready to go again.
A pronounced rubberised type button engages the lamp but thoughtfully a small, silver button makes toggling between modes so much easier especially when the the light is fixed to the bars. On paper 33 lumens is all that separates the TK15 from the PD31 at top whack but this doesn't account for the TK15's better operating range and more useable settings. Its 34mm lens and cowling belts out a very useable flood beam to around 220 metres-excellent for unlit lanes and trails but doesn't highlight the finer details; so not ideal for road duties. High (143) lumens seemed best in semi-rural to suburban contexts, balancing the need to see and be seen with reasonable economy. Dipping to mid returns a town friendly 47 lumens. Whatever context, the TK15 seems completely unaffected by vibration thanks to the internal stabilisation, although be sure to check the bracket periodically a lick of threadlock doesn't go amiss off road.
Another great torch that doubles as a powerful bike light.
road.cc test report
Make and model: Fenix TK15 Head 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
The Fenix TK15 is the latest addition to the TK range of lights.
New features for this light include a side switch for easy mode selection, without the need to adjust grip on the torch. Dual recoil absorbing springs ensure constant operation, and make this light ideal for weapon mounting.
The light can be powered by two CR123A or one 18650 rechargeable Li-ion cell. The TK 15 has a maximum output of 337 lumens with 4 output levels allowing the best selection of brightness and runtime plus high frequency strobe setting.
· Low Setting: 5 Lumens (142 hour runtime)
· Mid Setting: 47 Lumens (23 hour runtime)
· High Setting: 143 Lumens (6 hour runtime)
· Turbo Mode: 337 Lumens (1 hour 50 minute runtime)
· Strobe Mode: 337 Lumens"
Does pretty much what it says on the tin.
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 Lithium batteries or one 18650 Li-ion battery
· 135mm (Length) x 25.4mm (Diameter) x 34mm (Head)
· 152-gram weight (excluding batteries)
· Digitally regulated output - maintains constant brightness
· Reverse polarity protection, to protect from improper battery installation
· Tactical tail cap switch with momentary-on function
· Anti-roll, slip-resistant body design
· Made of durable aircraft-grade aluminum
· Premium Type III hard-anodized anti-abrasive finish
· Toughened ultra-clear glass lens with anti-reflective coating
Looks a little heath-robinson but very sturdy nonetheless.
Run times are very reasonable given the fuel source and retina burning prowess but invest in an aftermarket Li-on cell if used regularly.
Tell us how the light performed overall when used for its designed purpose
The TK15 makes a superb pannier/seatpack companion for long haul touring, mountain biking and urban exploration thanks to sheer power, build quality and flood beam. However,this isn't the best for blasting along metalled roads and run times suffer in the higher settings.
Tell us what you particularly liked about the light
Build quality and operating range.
Tell us what you particularly disliked about the light
Nothing given the design brief but running costs are high with dry cells and the switch seemed predisposed to accidental engagement.
Did you enjoy using the light? Yes
Would you consider buying the light? Possibly, with a redesigned switch and li-on battery
Would you recommend the light to a friend? Generally, yes
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)