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See.Sense Icon2 Front And Rear Light Set



Loaded with features, light and small, but with less-than-stellar output, this is a good about-town-slowly lightset
Two LED types for all-round and long-distance visibility
Tough, flexible mounting
Set-and-forget auto-on-off mode
App configuration, upgrades and alerts
Tilting mount positions
Ant+ pairing
No memory mode
'Crash Reporting' can be too sensitive off-road
Some upgrade niggles
Charge & run-times not quite as advertised
Can only connect one light via ANT+

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.

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

The See.Sense Icon2 light set is a worthy update to the Icon, which was an instant classic at launch. Compact, bright, and very intelligent, the Icon2 has a flexible yet very tough mounting system that easily adapts to different bikes. There are still a few niggles and it's not bright enough for fast, dark roads, but overall it's a good package, and is likely the best 'smart light' offer on the market today.

When Northern Ireland-based See.Sense launched the first Icon light back in 2015 Caroline gave it a whopping 4.5/5 – it was a genuine game-changer in the smart-bright-compact light space. Five years on, the Icon2 builds on that success, with a host of new features and improved performance.

> Buy this online here

The major physical difference is in the mount system. The old Icon used a rubber ladder strap, whereas the new Icon2 uses a clip-in bracket secured by a rubber O-ring, into which the light clips. There's an optional GoPro mount for £9.99, and two aero post mounts along with half a dozen O-rings of varying diameters to dial in the fit. The curved rubber block at the back of the mount is removable to re-orientate the bracket, meaning you can mount it vertically or horizontally on bars or seatposts. I used this config to get a horizontal mount on a rear rack, to good effect.

See Sense Icon 2 Front and Rear Lights - rear mounting position 1.jpg

The genius behind the clip-in bracket model is the four indentations down either side of the Icon2. The upper and lower indentations are angled, meaning no matter what your seatpost or other mount location angle, you can get a more-vertical vertical orientation, or you can locate the light higher or lower than the bracket mount point to clear a saddle clamp, seatpost clamp, to duck a handlebar computer etc.

See Sense Icon 2 Front and Rear Lights - rear mounting position 2.jpg

At first blush, the clip-in mount with a single thin O-ring seems far too weak to hold such an expensive light firmly – but don't be fooled, it's tough as boots. See.Sense has a video of the light fixed to a poor bike that is then hurled off a two-storey building – but stays attached. My own experience bashing about very rough trails on gravel and mountain bikes confirms the Icon2 isn't going anywhere.

Performance-wise the standout is the 400-lumen front and 300-lumen rear, driven out by a combination of two LED types – the 'CoB' LED panel that wraps around the light giving genuinely-bright 270-degree visibility, and the more traditional single CREE LED that blasts rearward via a lens for long-distance reach – but more on that later.


Charging is via a provided Micro USB cable into a very well-waterproofed port at the back – the light is rated IP67, meaning it'll survive anything up to and including riding your bike underwater at bog-snorkelling depth – but for no longer than 30 minutes, OK? Charge time from empty is about four and a half to five hours – considerably longer than See.Sense ’s advertised three hours. This was from a USB port tested as capable of 2.1A, but the lights only ever drew 210mA. With a charge capacity of around 970mAh, you can see why at that charge rate equates to a longer-than-advertised duration.

Charge level is shown by four green LEDs and one red embedded across the top of the light. You can quickly assess charge level with the light on or off, with a brief press of the button – the red one being last to stay lit when you're below 20%.

The Icon2 turns itself off after three minutes of zero movement – and it's really sensitive, so no fear of it doing this at a set of traffic lights. The lights go into a 'deep sleep' mode after 15 minutes of total inactivity. The sensitivity here is considerable, meaning the light needs to be really still – leaning your bike against a cafe frontage with the door being opened and closed will be enough to keep the light awake. The deep-sleep mode turns off Bluetooth broadcasting, and it instantly wakes on movement with the battery level LEDs lighting to signify awakeness.

Modes and operation

The Icon2 is operated by a single rubber-covered button which has wee 'wings' on either side that seem to serve no purpose but don't cause any problems either. The button is easily operated even through three layers of gloves, and negates the need to interact with the app in cold or wet weather.

See Sense Icon 2 Front and Rear Lights - front 1.jpg

One notable point is the partial memory mode – so if you have the light on, say, Constant or Eco modes, when you turn it off then back on using either the app or button, it defaults to the last-used of the four flashing modes – Flash, Twin, Burst or Pulse. It does remember the brightness level, which is a plus, but if you were wanting to run Constant or Eco modes, you'll need to press the button or use the app to cycle through.

See.Sense says, 'The core benefits of our technology is to vary the flash rate and brightness to optimise visibility and runtime. In all honesty, if you want a less bright light (ECO) or constant light there are cheaper options out there. It's also consistent with all of our other products to date, hence keeps the family consistency'. Fair enough.

The four main flashing modes named above really are down to personal preference – choosing one over the other didn't really seem to affect brightness or perceived ability to detect the light.


The modes are the same for the front and rear lights, but the rear also gets a 'Brake Light' mode, which claims to detect deceleration and changes half the COB panel from from flashing to full on for a number of seconds. See.Sense has a video on its site of this in action, but I must admit after quite a few hours of riding with the rear light on my bar so I could see any change, or following my son as he sped up, coasted and braked, this mode isn't really reliable/useful in my view.

See Sense Icon 2 Front and Rear Lights - rear 2.jpg

I've used a few other lights with similar 'brake light' functions, and they've all failed the real-world test – either being wildly over-sensitive, or not sensitive enough (as the case is here).


Another 'smart' feature of the Icon2 is its 'Crash Detection', which alerts an emergency contact with your location, should it detect what it thinks is a crash. The algorithm here needs to do some serious work to differentiate between bumpy ground, being lifted over a gate or fence, being leaned against a tree or other bike, and so on. If it detects a 'crash' an alert comes up on your phone – even if locked – saying there's a crash detected, and an SMS will be sent unless you swipe down to cancel within 30 seconds.

While it's a good idea, I could never seem to get to the 'swipe down' quickly enough – especially if wearing non-conductive gloves. Hence it was kind of a cry wolf situation after a while, me having to repeatedly message my wife to say no, I hadn't crashed, don't sell any bikes just yet. Fortunately during the test period I didn't actually crash per se, but did have a few occasions on my mountain bike where I might as well have, battering through rock gardens and over logs, and it seemed to pick those up. Again, like the brake light mode, I feel this one is maybe too hit-and-miss to rely on if you're expecting rescue. I'm open to seeing how reliable it is in a scientific test where people do actually throw their bikes off trails/road verges to see if it triggers an alert. Of course your phone needs to be in coverage too.

Stop thief!

The third smart mode is the theft alert, and this one works like a charm. If you walk more than about 20m away from your bike, or less if there are walls in the way, if the light is moved even a fraction you get an alert on your phone. It doesn't happen if you're close enough that the light thinks you are still around, so if you leave it outside a cafe where you're sat inside behind glass, likely you won't know someone's fiddling with your bike until they've ridden it 20 or so metres, but at least you (or more likely your mates) can give chase. Again you do need to be in Bluetooth range (about 70m I found in the open) for it to work. Also, once you set a 'home zone' in the app the theft alert won't trigger when you are in that zone – handy if other folks in your house might knock your bike.

Other smarts include insights via the 'My Stats' page, where as part of See.Sense ’s data analysis program the app can share things with you such as distance, average speed, calories/bananas (yes, bananas) burned, fuel saved, CO2 saved, and more. These insights are part of See.Sense ’s partnership with many cities to track and improve the lot of cyclists by capturing info such as road surface roughness, where people brake, average speeds, and the like. Part of the bargain here is that if you don't want to share your anonymised, GDPR-compliant data, you can't use the theft or crash alerts.

On the road

I'm fortunate to live opposite a dead-straight mile-long farm access road, so I dragged out an old bike stand festooned with various lights on a sunny day followed by dark Scottish evening to see who's who at the lumen zoo.

Firstly, I confirmed the Bluetooth range to be pretty much bang on 70m max for my iPhone 11 in a Quadlock case – your range may vary.

I compared the 400-lumen front Icon2 with a number of focused single-LED lights around the 400 lumen mark, and all stood out considerably brighter against the Icon2. The Icon2 won hands-down for side-on visibility, but that's not what you need for fast, rural roads, or commutes in cities through 40mph zones where oncoming headlights, car tail lights, traffic lights or shop-frontage lights are all competing for driver attention.

The 400-lumen front and 300-lumen rear would be great for being seen in the dark around town at lower (20mph) speeds and closer distances, where the wide-angle visibility alerts traffic side-on, but this dispersion of the available photons just doesn't cut it in daylight, or on the open road.

> Buyer’s Guide: The best 2019/2020 front lights for cycling

> Buyer’s Guide: 17 of the best rear lights for cycling

Matching up against the 600-lumen LED Cycliq Fly12 CE in medium flash mode, the Icon2 was decidedly dimmer – at 100m distance it would be swamped by surrounding light in an urban setting, where the Fly12 would cut through. And in daylight, at 100m, for a driver wearing sunglasses? The Icon2 was barely visible compared to the Fly12.

As a see-by light – nope, the spread-out nature again makes spotting potholes or drain covers a non-starter, even at slow speeds. To be fair See.Sense does state this in the FAQ.

Probably my best comparison is with a seven-year-old Lezyne Micro Drive Rear – a single LED thumb-sized light with only 70 lumens claimed. This is a light I've used for years to compare other rear lights to, and again, on the long straight road it won out easily – far brighter in both daylight and night-time than the 300-lumen Icon2 rear. Focused or wide-angle – choose one.


As far as battery life goes, it's pretty good. The app alerts you when either light gets to 20%, and I sometimes went a few weeks and a handful of rides without recharges, or in fact ever touching the lights – letting them go into deep sleep mode – then just hopping on the bike and riding.

As a rule of thumb I found a full charge good for about 8-12 hours of riding on 100% flash – so not as much as advertised, but then a fair bit of my riding was over gravel trails and estate tracks, where the sensors and algorithms were probably doing overtime because of the surface conditions and frequent braking. Then again, on a fast, smooth, e-assisted road ride the battery consumption was high compared to some gravel rides – indicating the algorithm was increasing brightness on the open road.

See.Sense states in the FAQ that because of Bluetooth broadcasting the Icon2 is good for about four weeks on standby, so while it's not a naughty boy, neither is it the set-and-forget Messiah of bike lights just yet. This seems at odds with the 'deep sleep' Bluetooth off mode mentioned earlier.

Light firmware updates are via the app, and for the most part are flawless, but there were a few hiccups, for which there is a good FAQ section on the support pages, which are the most comprehensive I've seen. I'd say don't do an upgrade just before you're about to ride – you might be delayed some time if it goes awry.

As with the original Icon, you can get the battery replaced for £25, which is a great offer for heavy users.


All in all, I like the Icon2 set – you just need to pick your use case. It's not what you want for fast, rural roads or mega-busy inner-city main roads. But for slower, twistier urban locations where side-on visibility, theft alerts, auto on-off and quick removal from the bike are key, it's a winner.


Loaded with features, light and small, but with less-than-stellar output, this is a good about-town-slowly lightset test report

Make and model: See.Sense Icon2 Front And Rear Set

Size tested: 300 lumen rear / 400 lumen front

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?

It's a lightset aimed at inner-city riders on slower roads, who value the smart stuff:

See.Sense says:

ICON2 is a light packed with more brightness and intelligence than ever before. It has 300 lumens in the rear light and 400 lumens in the front, gives you 16 hours of run-time in full power reactive flash mode, and shines powerfully in all lighting conditions, both day and night.


Each light contains two different types of LEDS (for both a focused and dispersed beam), makes you visible up to 3 km away, and gives you 270° of side visibility.


At riskier moments on the road (e.g. at junctions or approaching car headlights), ICON2 reacts by automatically flashing brighter and faster to make sure you stand out.


The See.Sense Mobile App lets you personalise your light settings and gives you low battery alerts straight to your phone. You can also pair ICON2 with cycling head units using ANT+.


Download the See.Sense mobile app, and join our community today, in order to...


ICON2's technology detects any road issues or unsafe routes you face on your ride. You can then share these ride insights via our app to help Planners upgrade roads and boost cycling safety.


Notify an emergency contact if you're in a crash, and receive notifications if your bike is moved when you're not there.


Our brand new Ride Stats feature includes your distance travelled, calories burned, fuel saved, fun facts about your rides and more unique stats.

Tell us some more about the technical aspects of the light set?

From See.Sense:


Lumens Rear: 300

Lumens Front: 400

Runtime: 16hrs on 'Reactive Flash'

Weight: 50 grams

Water Sealed: IP67 Rated


ICON2 automatically turns on when you move your bike and off after 3 minutes of inactivity.


Each light weighs under 50 grams (including its secure tool-less mounting) and is water sealed to IP67 standard.


ICON2 can adjust brightness levels to conserve battery life and IS easily recharged with any standard micro USB charger.


Each light comes with a standard seat post mount and an aero post mount, plus 5 mounting straps, making it easy to attach to any bike.


Always have the latest version of firmware by updating your light over-the-air via our app.

Rate the front light for quality of construction:
Rate the rear light for quality of construction:

Both built to really high quality levels.

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

Set-and-forget, literally. Just ride.

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

The click in and easy adjustment or swapping between bikes is best-in-class. Very well thought through.

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

Totally waterproof.

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

Both lasted well, but less than advertised. For the brightness and duration, they do pretty well – the smarts work in their favour here. Charge time is considerably longer than advertised, however.

Rate the front light for performance:
Rate the rear light for performance:

The headline lumen figures suggest a performance in excess of the real-world results. I feel See.Sense has erred too far on the side-visibility aspect to the detriment of distance front and rear.

Rate the front light for durability:
Rate the rear light for durability:

The build is really solid; I can't see them getting broken very easily at all.

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

Really light. Really.

Rate the light set for value:

£150 is a lot of dosh, but if you value the smarts, you can't get better.

Tell us how the lights performed overall when used for their designed purpose

Taken in the round, I'd say the value delivered is above average – not the brightest in a straight line, but if you understand these are a slower, more urban light you won't be disappointed.

Tell us what you particularly liked about the lights

The mount system – genius.

Tell us what you particularly disliked about the lights

The reach front and back just isn't as good as it should be in my view.

How does the price compare to that of similar products in the market, including ones recently tested on

You'll be hard-pressed to pay less than about £70 for a decent lightset like the Topeak Aero, but the Icon2 is on another planet feature set and build-quality-wise. Infini's Super Lava set is £60 and is a lot brighter, but again, zero smarts and far less side-on visibility. For £100 the Lezyne Connect Smart lights add in an app and decent functionality, and a much brighter front light. Twice the weight and the front light is a lot larger, mind.

Did you enjoy using the lights? Yes.

Would you consider buying the lights? Not for my main USP of road riding, no.

Would you recommend the lights to a friend? If they wanted a smart, light, tough lightset for about town, yes.

Use this box to explain your overall score

There's a lot to factor in – a ton of functionality obviously, but boiling it all down the Icon2 just isn't as bright day or night as it needs to be, in my view. Clearly See.Sense has gone with a small, light build, and that inevitably impacts output and run-time. I think many people would have preferred a brighter beam front/back, less to the side, and maybe more heft in return for the same battery life. The mount is awesome, they are very small, light and last for ages – all benefits for commuters – but compared with the likes of the £100 Lezyne Connect Smart set, I'm struggling to go with more than a 3.5/5 'Good' here.

Overall rating: 7/10

About the tester

Age: 46  Height: 183cm  Weight: 72kg

I usually ride: Merida Ride 5000 Disc  My best bike is: Velocite Selene

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, mtb, Dutch bike pootling.

Living in the Highlands, Mike is constantly finding innovative and usually cold/wet ways to accelerate the degradation of cycling kit. At his happiest in a warm workshop holding an anodised tool of high repute, Mike's been taking bikes apart and (mostly) putting them back together for forty years. With a day job in global IT (he's not completely sure what that means either) and having run a boutique cycle service business on the side for a decade, bikes are his escape into the practical and life-changing for his customers.

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coloman | 3 years ago

I love this light, and the customer service is superb. I don't leave my hosue without the rear light on

wycombewheeler | 3 years ago
1 like

It seems to me that it should be easy to differentiate an actual crash from a false alarm. As in an actual crash the excess acceleration/deceleration will be followed by zero movement,as the bike is lying on the floor. If the light is functional and detecting movement 1 minute after the 'crash' then no need to send a message.

You'd also think that a light linked to a phone app would be able to initiate a warning - "light lost or battery flat" so the rider knows they don't have a rear lioght any more.

Xenophon2 | 3 years ago

I'm sold on the rear light, not the front.

Rear light is brilliant and well worth the hefty price point.  I had doubts about the bracket but it never, ever fell off.  Autonomy in 'low flash' mode is about 7 hours but it does take long to recharge, 3 hours minimum and I'm guessing it's more like 4.  The 'brake light' function appears to work ok, at least that's what a couple of mates tell me.

The front light...well...I don't see the point except as 'light for being seen' where it performs well.  But it's useless for riding on unlit or potholed roads, just forget about that.


IanGlasgow | 3 years ago
1 like

RE: "At first blush, the clip-in mount with a single thin O-ring seems far too weak to hold such an expensive light firmly – but don't be fooled"

I had an Icon 2 rear light for three weeks.
It fell off three times - the third time I didn't know about it until I got home.

See.Sense sent me the videos of their lights not falling off. I felt like I'd been gaslighted. I've never seen any other light manufacturer feel the need to make videos of their lights not falling off. Methinks they doth protest too much.

My daughter has the Ace which, like the original Icon is smaller and uses the same attachment. The Icon 2 seems to be too big for this fitting to hold it steady so it waggles about and falls off if you hit a bump.
I absolutely would not attach it by the bottom of the light (as shown in the first pic) or adapt it to attach to a rear rack - that's where mine was, following the advice I got from See.Sense before I bought it - they suddenly seemed a lot less helpful after it fell off)

They did offer me a half price replacement (I didn't take them up on the offer - even at half price it's a lot of money for a light that falls off once a week).
They pretty much permanently offer discounts to all kinds of people (including 30% off for Cycling UK members) suggesting their lights are overpriced.

While it wasn't falling off it was a decent light with a disappointing battery life - it seemed to lose charge while not in use. See.Sense claim to have updated the firmware to solve this problem.
Also, the crash alert feature didn't work; mine fell off three times and never sent an alert. I guess on the third occasion it was too far from my phone to register, but on the other two occasions I heard it fall and stopped immediately so it never lost contact with the phone.

I like the concept; a light bright enough to be used as a DRL with a long battery life and some smart features. I replaced it with a set of Cycliqs (which are great apart from the battery life) and Planet-X's Double-Enders as backup (which cost £1.60 for a set of two, have an incredibly long battery life and are cheap enough to be left permanently on the bike).

"the clip-in mount with a single thin O-ring seems far too weak.."
I've not got an Ace (picked it up cheap in a sale) which uses the same mount. So far I've broken two of the stupid little rubber bands.
I thought it'd be a great spare light, unfortunately because you can't switch bluetooth off (my Cycliq has an airplance mode that turns Bluetooth off) so it's constantly looking for a connection, the battery runs down in your bag. It's useless for occasional use as a spare.

Awavey replied to IanGlasgow | 3 years ago

Yes very true on the battery consumption when it's not in use,must be the bluetooth scanning constantly and not going into sleep mode as i went to use my lights last week having left it with a full charge 8weeks ago,and it was as flat as a hedgehog on the road

KiwiMike replied to IanGlasgow | 3 years ago
1 like

I can only repeat that in 3 months and likely a thousand miles of really rough trails and highland estate 4x4 tracks at high speeds, on an unsuspended bike, neither light came loose. Your experience sounds like a faulty bracket?

Awavey | 3 years ago

They are a decent option for lights to be seen by others on the roads,almost like navigation lights really,but dont expect the front to be any use as a light to illuminate your way with, and fwiw the Android app to control the lights is still rubbish doesnt work properly,frequently crashes and only a beta after 4 years

Fluffed | 3 years ago

currently 60 quid off on see.sense site

Sriracha | 4 years ago
1 like

Looks good, but at that price it would have to a keeper for some years. Might sound petty, but no way am I being tied into micro-USB anything for the next several years.

Freddy56 | 4 years ago

I'm a fan. Dont realy leave the house with the rear. Never used the app, just on charge and auto off, but cars DO give you more space, it think because the see you earlier.

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