The Lezyne KTV Drive Front is a charming wee Be-Seen-By front light, with some neat features that make the whole package pretty compelling.
The single white LED is fixed at 15 lumens. This isn't a tarmac-scorcher, but you get a minimum runtime of over four hours on constant. That bumps up to over six hours for the pulse mode where the brightness varies but never goes out, and over ten hours in either of the three flashing modes. This from a light with the dimensions of a Matchbox car and weighing just 51g on the Road.CC Kitchen Scales Of Semi-Truth.
A matching KTV Drive Rear is exactly the same price and size, excepting it sports a red LED. It has half the power (7 lumens) and an hour less runtime in each mode. The advice from Lezyne is that red LED's consume more power as they are 'significantly less efficient' than white LEDs, which operate on a different wavelength. Who knew?
In form factor the KTV is a fairly unique beastie, resembling nothing so much as the monolith from 2001 - if it were also available in silver, red or blue as well as black. The body is aluminium and rubber, with a plastic lens. At the back there's the tried-and-tested Lezyne 'Clip-On' system clip common across their range of smaller lights, with the ability to slide over a fabric loop on a barbag (or a saddlebag/backpack, if using the red version). Most will use the laddered rubber strap that can stretch around the fattest of handlebars. The clip is concave to sit nicely against a curved surface and holds one end of the rubber strap captive. Once the strap is hooked around the bar and over the clip the KTV is then rotated 90 degrees to effectively lock it in place, ensuring there's absolutely no chance of it coming unstuck.
The whole operation takes seconds, which will be welcomed by commuters or café racers needing to strip and re-fit lights several times a day when leaving their bikes unattended. If you have both shifter and brake cables emerging under your bar tape you may need to play around a bit to get the fit right - it was ever thus with bar-mounted lights.
The business end of the KTV is a single LED focused through a protruding, almost fish-eyed rectangular lens. The light pattern this throws out is akin to what you'd imagine a Battlestar Galactica Cylon centurion's field of vision to be - a horizontal strip 90 degrees wide, with nothing wasted up or down. Check out the Road.CC Light Comparison Engine for the technical lowdown.
This optimisation of scarce Lumens is a great way to punch above your visibility weight while keeping real weight down and runtime up. Among urban clutter and car headlights the KTV marks you out at distances up to 100m, which is pretty good for a light of this size. Be certain though - this light is not bright enough to 'cycle by' on unlit roads, and Lezyne market it solely as a 'safety light'. 15 Lumens focused into a spot might be enough to ride by, just. But definitely not when spread out.
The KTV's unique form factor, beam spread, run time and low weight would make it an excellent light for camping or bikepacking. It could easily be hung from a tent roof, sat on a camp table or clipped to your top/belt/Buff headband for nocturnal fettling.
Charging is via a built-in USB plug hidden underneath a solid rubber bung, so potentially no cable required. In practice the 10mm of body protruding either side and below the USB plug means you may need a few spare ports or a USB extension cable in order to get more juice onboard from today's thin laptops. Time to charge from flat is three hours on a two-amp dedicated charging socket, or four hours from a standard laptop USB port The red charging LED is visible through the front lens, so you get a good indication of when it's done as it changes to green.
The plug itself looks well-protected by the rubber cap and could probably survive being dropped in a puddle if retrieved sharpish. No IP rating is given beyond the boilerplate '...precision engineered and manufactured with quality to deliver extreme weather and water resistance'. The USB cover comes off with a satisfying 'pop', implying there's a degree of airtightness to the whole package.
The KTV is operated by a single raised rubber button on top. A quick press and release gives you the battery level through one or both small windows in the top of the light. These allow enough light from the main LED to shine through, giving you a visual confirmation that the light is operating. In addition an extra colour (green on the left, red on the right) shows battery level. Green only is 75-100%, green + red is 75-25%, and red only is below 25%. The battery level is visible constantly during operation so you get plenty of warning, although it stands out best in the flashing modes where the main LED goes out completely. The coloured LED's are just bright enough to make out while riding in daylight.
Holding down the button for two seconds turns the KTV Drive on in slow flash mode - once a second. Another press doubles that into what is probably the best flashing mode, and a third press puts you into not-quite-disco mode. The fourth press is 'Pulse' mode where the light - er - pulses, about twice a second. The fifth press turns the light on constantly.
One feature that really should be standard on all lights is that they turn back on where you left off - particularly with five modes to choose from. If you like always-on, you'll have to get used to pressing the button five times, each time. A one-second press turns the KTV off. Come on bike light industry, we've landed a probe on a spinning comet for science's sake. How hard can it be to remember the last setting used?
The main use for this light is as a front flasher and it excels with a run time of over 10 hours in any of the three 50:50 on-off flashing modes. The advertised time is 9 hours 30 minutes; good to see Lezyne exceeding expectations. In constant mode run time was just over four hours; less than the advertised 4 hours 30 minutes but as always-on is a niche use case for a light of this type that's a minor concern. The percentage split between the charge levels isn't as accurate as advertised, with red ('below 25%') only lasting 15 minutes in the always-on mode, when it should be an hour.
Unlike high-end Lezyne models the light output is not guaranteed to be constant. In the four-hour always-on mode Lezyne advise it stays above 15 Lumens for 2.5 hours, decreases to 12 Lumens for the next 1.5 hours, then gradually decreases until the battery is drained. In testing the output at the cut-off was still plenty bright enough to be noticed from a decent distance away due to the focused lens. In flashing mode the output would be 15 lumens over six hours, then 12 for most of the remaining four.
In short: it's plenty bright enough to be seen by and lasts ages.
So where did Lezyne get the idea for a name like 'KTV'? In a market filled with SolarMegaBlasta2000's or MicroNanoFlealights, KTV stands out in its non-adherence to the norms of inferring retina-melting power or sub-atomic stature. In East Asia 'KTV' refers to a Karaoke club - with or without 'services' available. A suitable meme for a bike light to channel? The best explanation is left to Lezyne's Sam Chau:
'The KTV light was created to bring a 'unique personality' into our LED line, challenging the norm and conventionality of what's currently in the market... There can be a lot of interpretations but in the end it should all conclusively be blissful and happy. Going to a KTV is like going to a sanctuary – it can be a place to relax, a place to have fun, and a place to celebrate... When a consumer purchases this product for their night ride, we hope they can bring this positive energy with them – just be happy.'
With the performance, design and engineering shown in the KTV, Lezyne appear to have pretty much nailed that positive, happy vibe.
Verdict
Small, innovative and well-executed front be-seen-by light that's a pleasure to use
The light comparator
If you have a nice big screen you can click here for the widescreen version (1400x1000px)
road.cc test report
Make and model: Lezyne KTV Drive front light
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?
People needing a conspicuous yet small flashing light that lasts ages.
Lezyne say: The Lezyne KTV Drive Front is a bright, ultra-compact, 15 lumen safety light. The machined aluminium body is lightweight, durable, and extremely weather-resistant. The Composite Matrix back clip features the Clip-On System, with movable clip, for versatile strapped or clipped mounting. The multi-position silicon rubber strap attaches directly to the back plate to secure the light to a wide range of handle bar diameters. The Side Visibility lens extends beyond the body providing 180 degrees visibility, and increasing user safety. The bottom cap can be removed to reveal its integrated USB stick, making recharging convenient and cable free. The KTV Drive Front is available as a single front LED, or as a front/rear pair (KTV Drive Front and Rear).
Tell us some more about the technical aspects of the light?
It's a single 15-lumen LED, with a non-replaceable battery charged via a fixed USB plug - no cable required. Runtime is over 10 hours on flashing mode, 4 on solid.
Rate the light for quality of construction:
10/10
It's so nicely made you want to fondle it.
Rate the light for design and ease of use. How simple was the light to use?
8/10
Press the button - doesn't get much easier than that. Not remembering the last mode used is the only drawback to the entire light.
Rate the light for the design and usability of the clamping system/s
9/10
Works excellently. Very quick to add or remove.
Rate the light for waterproofing. How did it stand up to the elements?
8/10
It's not IP-rated, but then no Lezyne lights are as far as I know. That said I own aboutsix of their lights and none have ever failed in the wet.
Rate the light for battery life. How long did it last? How long did it take to recharge?
8/10
Charging and discharging were predictable and balanced, overall.
Rate the light for performance:
9/10
For the size and power the focused beam is highly visible over a very wide angle.
Rate the light for durability:
8/10
It feels very solidly-made. No durability issues are foreseen.
Rate the light for weight, if applicable:
9/10
It's very light for what it does.
Rate the light for value:
10/10
At £15.99 RRP this light is a bargain.
Tell us how the light performed overall when used for its designed purpose
Can't fault it - bright from a goodly distance, small, light, solid mount.
Tell us what you particularly liked about the light
The beam. The unique pattern works really well.
Tell us what you particularly disliked about the light
Nothing.
Did you enjoy using the light? Yes.
Would you consider buying the light? Yes.
Would you recommend the light to a friend? Yes, definitely.
Anything further to say about the light in conclusion?
Add 'last mode' remembering & it'd be 5 stars.
Age: 41 Height: 183cm Weight: 73KG
I usually ride: Charge Juicer My best bike is:
I've been riding for: Over 20 years I ride: A few times a week I would class myself as: Expert
I regularly do the following types of riding: club rides, general fitness riding, fixed/singlespeed, mtb, MTB, singlespeed and Dutch bike pootling
Add new comment
6 comments
Just got one of these to supplement my Macro Drive. I usually have the Macro on flash so the pulse mode on this should be a useful addition.
The light comparator is great for seeing how much a light "lights-up" the road in front of you. What it doesn't do is show us how visible a light is when you look towards it from different angles.
We have no way of telling if this light is visible from a car pulling out of a side road, for example. It is this kind of comparison we really need.
If you look at the comparison engine, you can get an idea of this measure. For example, the KTV is twice the lumens of the B'Twin 520 at 1m off-axis horizontally.
Whilst this is an important metric, it's very hard to quantify - and its effectiveness impossible to quantify. I'd say the KTV has the best side visibility out there for its size/weight/cost/output due to the deliberately horizontal beam shape.
For my money, a helmet-mounted light is the real way to get side-road visibility, when you *look* at cars. A side-lighting feature will almost inevitably be blocked at some angle by your hands/arms/hoods/etc. I'd also never rely on either.
Screenshot 2014-12-08 11.21.01.png
interesting about the relative efficiencies of white and red LEDs. So is there a reason you couldn't put a white LED behind a red lens for the same effect but increased run time?
The response from Lezyne (via Twitter) as to why the red light isn't a more efficient white LED + red lens is:
"Red+red lens more efficient for color and lumen. White+red lens looks pink. To get same output of red+red, the white+red have to be driven harder so would be worse runtime"
i have the lezyne combined white ahead/ red rear helmet light. the rear is a red led through a red cap. if you put the red cap over the front white light it is a very pale pink, not red. suspect that if you make the red lens/ cap think enough to keep it red the increase in brightness necessary to get the same lumens output would more than offset the efficiency gain. one assumes they ain't numpties!