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The Knog Frog Strobe Twinpack in black is a low-cost yet user-friendly solution to maintain legal compliance when riding a bicycle at night. In a pinch you can see by the front light too.
Knog is an Australian bike accessory brand with an eye for quirky yet user-friendly design, and the Frog lights are a good example of this. Low cost yet usable, they do the job they set out to, and do it well.
Using CR2032 button cells means the Frogs aren't going to set the road on fire, hence I class these as 'legal compliance' lights – too weak to use in unlit situations, and nowhere near bright enough to reliably grab a motorist's attention. I did find myself navigating a completely unlit path one evening, and the front light was perfectly adequate to walk by, or maybe cycle at jogging pace – but don't expect miracles.
The white front claims 8.5 lumens and 80hrs flashing or 50hrs steady, the red rear 2.5 lumens for a run-time of 70hrs flashing and 40hrs steady. This discrepancy in output is down to red LEDs being less efficient than white. Frog's user guide claims there's a low battery indicator that comes on after a number of hours, showing as a red LED in the lens, but in a test running the lights from full to flat I didn't see it come on.
In terms of run-time, expect to get about 30 hours before the output begins to drop away appreciably – but let's face it, run-time is dependent on the quality of your button cell supply.
Both the white front and red rear have three flashing modes: slow, interrupted and fast flash, plus constantly on. Modes are selected by cycling through with a single click of the button, with a final click turning the light off. Of more interest will be the ability to turn off while remembering the last mode, with a long press. Then a single press will turn on at the last-used mode.
The buttons are underneath the one-piece silicone rubber body, but are prone to inadvertent actuation – so if you're piling them into a rucksack you might want to have a small plastic container to pop them into.
All in all, you can do worse than the Knog Frogs as legal-compliance lights that won't annoy you by needing endless button presses to get to your chosen mode of operation, and they fit on/off the bike quickly too.
A good choice to keep you legally-compliant when riding at night
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road.cc test report
Make and model: Knog Frog Strobe Twinpack
Size tested: 80x35x42mm
Tell us what the light set 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?
Tiny, quick-to-remove low-profile lights to keep you legal and get you out of a pinch.
Knog says: "Houston - 1987: a lab frog escapes from its enclosure and knocks a vile of stinky chemical gunk onto an unsuspecting LED, giving it special powers. The light escaped to a nearby medium security retirement home, where it spawned an army of multi-coloured freaks, hidden from civilization... until now."
Tell us some more about the technical aspects of the light set?
LIGHT OUTPUT : FRONT 8.5 lumens // REAR 2.5 lumens
DIMENSIONS : 80 x 35 x 42 mm
WEIGHT : 19g
RUN TIMES : FRONT 80 hrs (flashing), 50 hrs (steady) // REAR 70 hrs (flashing), 40 hrs (steady).
The rubber is tactile and strong, and the hook at the rear is chunky. I can't imagine breaking these.
Press the button to turn on or change modes. Press and hold to turn off. Simples.
Stayed put. Fast.
The run-time for new CR2032s was correct – 30hrs on full.
These really are more legal-compliance lights than anything else, and they do that job to an above-average level.
Can't see them failing anytime soon.
They weigh basically nothing.
Tell us how the lights performed overall when used for their designed purpose
As legal compliance lights for less than a tenner per end, they do the job.
Tell us what you particularly liked about the lights
The simplicity of mounting. And the low battery indicator.
Tell us what you particularly disliked about the lights
Did you enjoy using the lights? Yes
Would you consider buying the lights? Yes
Would you recommend the lights to a friend? Yes
Use this box to explain your score
I call them above-average due to the memory mode, and the quick on-off rubber strap.
About the tester
I usually ride: Merida Ride 5000 Disc 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: cyclo-cross, club rides, general fitness riding, mountain biking, Dutch bike pootling