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Verdict: 
A good choice to keep you legally-compliant when riding at night
Weight: 
19g
Knog Frog Strobe Twinpack
6 10

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.

> Find your nearest dealer here

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.

Knog Light Frog Strobe Twin pack Black - front.jpg

Knog Light Frog Strobe Twin pack Black - front.jpg

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.

> Need a powerful front light?

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.

Knog Light Frog Strobe Twin pack Black - rear.jpg

Knog Light Frog Strobe Twin pack Black - rear.jpg

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.

> Read more road.cc reviews of light sets here 

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.

Verdict

A good choice to keep you legally-compliant when riding at night

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).

Rate the front light for quality of construction:
 
9/10
Rate the rear light for quality of construction:
 
9/10

The rubber is tactile and strong, and the hook at the rear is chunky. I can't imagine breaking these.

Rate the light set for design and ease of use. How simple were the lights to use?
 
9/10

Press the button to turn on or change modes. Press and hold to turn off. Simples.

Rate the front light for the design and usability of the clamping system
 
10/10
Rate the rear light for the design and usability of the clamping system
 
10/10

Stayed put. Fast.

Rate the front light for waterproofing. How did it stand up to the elements?
 
10/10
Rate the front light for waterproofing. How did it stand up to the elements?
 
10/10

Survived dunkings.

Rate the front light for battery life. How long did it last? How long did it take to recharge?
 
8/10
Rate the rear light for battery life. How long did it last? How long did it take to recharge?
 
8/10

The run-time for new CR2032s was correct – 30hrs on full.

Rate the front light for performance:
 
6/10
Rate the rear light for performance:
 
6/10

These really are more legal-compliance lights than anything else, and they do that job to an above-average level.

Rate the front light for durability:
 
9/10
Rate the rear light for durability:
 
9/10

Can't see them failing anytime soon.

Rate the front light for weight:
 
10/10
Rate the rear light for weight:
 
10/10

They weigh basically nothing.

Rate the light set for value:
 
8/10

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

Nothing, really.

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.

Overall rating: 6/10

About the tester

Age: 43  Height: 183cm  Weight: 72kg

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

8 comments

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multimodal [56 posts] 1 year ago
1 like

For those with kids, these lights are brilliant for microscooters.

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Redvee [363 posts] 1 year ago
0 likes

£18.99 for a set, a quick search has found them for £7.50 + postage for a pair.

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KendalRed [98 posts] 1 year ago
0 likes

I've had a few of these over the years, and like most of these silicon based thingys they don't last more than a season or two - the rubber arms split or they suffer from water ingress eventually, but the low cost means it's not too much to replace (although not that environmentally friendly if you're chucking them away every other year!).

I tend to strap mine to the front fork and rear seatstays to augment proper lights.

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StoopidUserName [356 posts] 1 year ago
0 likes

I had a couple of these a few years back. Found them really unreliable which is a shame as they were a nice backup light when working. Maybe they've updated the design?

 

I now have a couple of decathlon lights very similar to this which I keep as spares in my bag. £2.99 each or something stupid. I keep the bit of plastic inbetween the battery and connectors to stop them coming on accidently and running down the battery.

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hylozoist [66 posts] 1 year ago
0 likes

These are useful little backup lights, although they've been known to turn themselves on in my bag and are flat when I want to use them. But, Knog - where's my Oi?

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Redvee [363 posts] 1 year ago
0 likes
hylozoist wrote:

But, Knog - where's my Oi?

 

I've had mine since 31/10.

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cczmark [21 posts] 1 year ago
0 likes

Should knock another star off for using non-rechargeable batteries. As an absolute emergency they are nice and lightweight though. You can get similar lights from PlanetX (Phaart brand) for £2.99 or the real Knogs at a discount.

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joules1975 [483 posts] 1 year ago
0 likes

In my experience, they often come on accidentally when stored,  are useless in the wet, and don't run for that long due to the use of the non-rechargable and relatively expensive coin batteries, so while they are definately better than the cheaper copies, unless Knog have improved the design (which it looks like they haven't) they are not worth £18+ AND three stars.

£12 RRP and then three stars maybe valid.