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Knog Frog Strobe Front Light



A great light, with some flaws

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

What the scores mean

Good scores are more common than bad, because fortunately good products are more common than bad.

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  • Excellent
  • Very Good
  • Good
  • Quite good
  • Average
  • Not so good
  • Poor
  • Bad
  • Appalling

Knog's cheeky, no-nonsense approach to LEDs made a splash when they hit the UK a few years back with the Frog. The Aussie company had solved the problem of complicated fixings and brackets to keep your light and bicycle in happy attachment. Plus, they were fun and simple.

Since then Knog have developed their product range impressively. These Knog Frog Strobes - arriving at in front-and-rear tag team - are an evolution of the original Knog Frogs, the small single LEDs encased in stretchy, easy-to-attach silicone that were the company's first hit.

The new Frog Strobes are a definite improvement on the old version. They're still small, light and handy, and keep the same tactile, colourful casing, as well as the same stretchy loop-and-hook arrangement that makes them a doddle to mount securely, to take off and to switch between bikes. It also makes them simple to mount on to any part of your bike you want.

New for 2012 are the four, rather than two, light settings: single flash; double flash; constant flashing; and always lit. They're also 2.5 times more powerful, if my millicandelas-to-lumens calculations are correct, than the old ones. That gives them a bit more welly but, even so, they're not very bright. Unless you live in a seriously well-lit place, for cautious or very safety-conscious cyclists this is probably only a back-up light.

So keep it stowed away somewhere with you, in case you get caught out after hours, right? Hmmm. The rather large on/off button on the top is all too easily triggered by other things in your pocket or bag. I've pulled the front and rear pair out of my bag a couple of times and found one flashing away. So, if you do use them as back-up, there's a risk they'll have discharged a chunk or all of their battery life since you last used them. I've used a lot of Knog lights, and this is also a problem with the bigger ones.

The other problem I've experienced with Knog lights over the years is one of reliability, I've had a couple of pairs of Bullrogs just fall off, which okay could be pilot error, my Knog Skinks proved not to be waterproof when mounted what I presume to be was the right way up, the Gekkos I've owned have been the worst culprits for simply turning on in your bag and my Boomer went on the blink straight from the box.. and not in a good way. Maybe it's just me, or the vagaries of the postal system but one of the pair of test Frogs I was sent continued this unhappy record from the off it wouldn't turn off reliably, and would start blinking again of its own accord. Of course, Knog would replace a faulty product straight away, if you took it back to the shop, something I never managed to.

All that said, these are fun, useful and, for a tenner mine proved capable of resisting the worst of the rain and despite getting turned on accidentally the batteries lasted well and are cheap to replace, so pretty good value. All lights come and go - they're probably the most-replaced part of a commuting cyclist's armoury - but an LED of any price shouldn't be a throwaway purchase - which some of my Knogs have felt like… although that didn't stop me buying a rear Frog Strobe to replace the test one that didn't work.


A great light, with some flaws test report

Make and model: Knog Frog Strobe Front Light

Size tested: Green

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?

A back-up light for urban riders. The website isn't that helpful on that one

"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?

It's a bit better on the technical aspects:

"Water-resistant, flexible silicone body, integrated clipping feature, quick-release mounting. Visible up to 600 metres. 12 HOT colours (look out for random special colour releases). Note: Safety light only

BURN TIME 80 hrs (flashing), 50 hrs (steady)

DIMENSIONS 80 x 35 x 42 mm

WEIGHT 19 grams (including batteries)

BATTERIES 2 coin cell - CR2032 included

LED SPECS Hi Powered surface mounted LED strobe system with lens

LIGHT OUTPUT 25 lumens

MODES 1. Strobe 2. DISCO Strobe 3. Strobe Pulse 4. Constant"

Rate the light for quality of construction:

One of them arrived broken, though faulty products would of course be replaced by the manufacturer.

Rate the light for design and ease of use. How simple was the light to use?

I like the silicone, but design-wise, the easily triggered on/off button is a big no-no.

Rate the light for the design and usability of the clamping system/s

I love the stretchy strap and hook system. Makes it simple to mount anywhere.

Rate the light for waterproofing. How did it stand up to the elements?
Rate the light for battery life. How long did it last? How long did it take to recharge?
Rate the light for performance:

An improvement on the previous version, but still relatively weedy. It's only a back-up light though.

Rate the light for durability:
Rate the light for weight, if applicable:
Rate the light for value:

Tell us how the light performed overall when used for its designed purpose

Great on the bike, bad in the bag or the pocket.

Did you enjoy using the light? Yes

Would you consider buying the light? Yes

Would you recommend the light to a friend? With caveats

Anything further to say about the light in conclusion?

I still have a lot of goodwill towards Knogs. They're a great idea, but in my experience the initial leap forward their stretchy casing represented, hasn't been followed through 100% in other areas of the product design.

Overall rating: 6/10

About the tester

Age: 31  Height: 1.78m  Weight: 65kg

I usually ride: Cinelli Strato road or fixed commuter hack.  My best bike is:

I've been riding for: 10-20 years  I ride: Every day  I would class myself as: Expert

I regularly do the following types of riding: commuting, club rides, sportives, fixed/singlespeed,


Add new comment


davel | 6 years ago

The places that are still selling them are very clearly stating 8.5 lumens, and some are not even selling them for a tenner... But someone wants a refund from a 5 year-old review?

Why did you focus on this review, and not this one, from just under a year ago, and which comes up right next to it in Google, for me:

Anyway, my favourite part is the True Story of the escaping frog. If that turns out to be out-of-date, I can see me suing.

alansmurphy | 6 years ago

"They're also 2.5 times more powerful, if my millicandelas-to-lumens calculations are correct, than the old ones. That gives them a bit more welly but, even so, they're not very bright."

Think someone got confused and goes by the last 4 words...

fenix | 6 years ago

What's your point Frankie ? Who's lying ? I don't follow.

Who wants refunds ? The people who bought themon your advice ? The review says they're not very bright.

What do you expect for a fiver ?

frankierae | 6 years ago

How can you consciously publish false brightness ratings and get away with it?

I've just recommended these to 12 riders for my work charity ride due to the amazing size to brightness ratio at 25 lumens!

There must be some sort of law against paid-for-advertising lying journalists like you. Who's going to refund the people who just bought them? Who do we speak to? Trading Standards? I'm guessing not as being a review site you're probably not trading and know you can do this without legal recourse. Shame on you.

Mr Will | 12 years ago

I've had several of these over the years and somehow love them despite their shortcomings.

The main problem is that they are definitely water resistant, rather than waterproof, so need to be mounted somewhere where they are protected from the worst of the spray (I've had a couple pack in this way).

They are also definitely for being seen, rather than seeing with, so don't expect them to be up to countryside night rides.

The batteries can also be a bit pricey from normal stores, but this was solved by buying a pack of 100 off ebay for a tenner (they don't last quite as long as duracells, but at that price - who cares).

Finally, they do start to get dim when the batteries get low, which makes regular replacement a must rather than waiting for them to expire completely.

Despite all these problems, I still love the size, ease of fitting and swapping between bikes and the fact that there are no ugly brackets left behind during daylight rides. My next set of lights will probably be something with a bit more oomph, but I'll still make sure I have a pair of Frogs in my bag as backups.

Coleman | 12 years ago

My Knog front light packed in within a week of purchase. It hadn't been in the wet and hadn't been dropped. For supplemental lights I usually buy cheapies from Clas Ohlson. I won't be in a rush to buy Knog again.

Giant Rob | 12 years ago

I have got both a Strobe front and rear light for everyday riding. I first saw the rear light from a 100 meters or so when I was following a guy who had one so I purchased one straight away. Both the lights are very good as they pulse/flash very brightly. The setting I like is when the light pulses several times and then misses a beat. This certainly is an attention grabber and it can be seen for quite a distance. The rear light certainly is bright and is the one I use the most. Please be aware the lights aren't for lighting the way for the rider and only drawing attention to yourself. I think they are great.

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