Exposure Sirius 11 review: Big performance in a small and refined package

The Exposure Sirius 11 represents Exposure’s most powerful commuter road light that packs enough of a punch to be able to be used on rural roads at higher speeds. It doesn’t feature the huge lumens and smart functionality of the Exposure Strada range, but is far smaller and compact making it more suitable for commuting.

Fast charging and broad range of light modes add to the practicality, while an array of easy mounting options are available. For those who do bikepacking, it can be used while connected to a power pack, but is limited in the intensity it can maintain.

Featuring Exposure Lights’ signature machine aluminium body gives a premium look and feel, but adds functionality too, with greater heat dissipation capacity. This does all come at quire a premium price, especially when looking at similar specification lights available at the moment. But with a strong reputation for product longevity and customer support, that initial price does start to look more justified and it mixes it with the best bike lights on the market.

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Design and Specification

The Exposure Sirius 11 stands out quite nicely from the crowd thanks to the gunmetal grey CNC machined 6063 aluminium body. This 6063 term relates to the type of aluminium alloy, and this specification is known for corrosion resistance, and capacity for a high quality surface finish. Indeed the intricate detailing looks sublime and premium, but it has an added purpose.

Aluminium is known for greater thermal transfer properties, i.e the ability to disperse heat. Given that higher power lights produce more heat, and a buildup of that heat can damage the battery, having a greater capacity to disperse that heat is vital. Add to that the machined gills which increase the surface area for greater heat transfer; form and function beautifully blended into one.

Other external features include the protruding lip over the light to reduce glare for both the rider and other road users. Meanwhile the Sirius 11 uses USB C charging under a rubber port, and the control button is now metal rather than rubber. The light can actually be charged up from flat in around 2-hours thanks to fast charging. Previous Exposure owners, myself included, might remember the excessive charge times required for high powered bike lights of old. It can also be charged and used simultaneously with a power bank.

Going beneath the surface, the light has a lot of other smart features going on. First and foremost, for a light weighing just 71g it packs an impressive 1300 lumens. This comes from a single Cree XHP35.2 LED. This uses a precise 8° collimated beam (mostly parallel light rays, to you and I) to create a high range spot light functionality, while the commuter lens cap allows for 270° side visibility.

The light features a total of 9 modes, using 3 separate schemes with 3 modes each. Each scheme has a High, Low, and Flash setting with different lumens and run times. On the highest 1300 constant lumen setting a 1 hour life is given, while on the lowest power flash mode 130 hours is the claimed run time. This is all controlled via the single control button on the rear of the light. At the rear you can check the battery life with a single button press to reveal green, amber or red to determine battery level.

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Two of the flash modes use Exposure’s DayBright function, a bespoke pulse pattern that makes the user more conspicuous and is claimed to be visible from a kilometer away even in bright sun. Other smart features include Intelligent Thermal Management. This is patented circuitry within the light will reduce power to the LEDs if they go beyond the optimum temperature, optimising performance and battery life. Once back to a normal temperature brightness will increase.

To make the light usable on or off the roads, it has both an IK09 impact rating and IP67 waterproof rating. What these mean, respectively, is that the light can withstand a 10 joule impact – equivalent to a 5kg weight dropped from 20cm – as well as having the highest level dust protection and water submersion, of up to 30 minutes in 1m deep water. This is more than most bike lights will ever have to realistically deal with.

Included with the light is a handlebar mount and band, the light itself, and a USB-C to USB-C charging cable. The packaging is entirely recyclable.

Performance

I was fortunately provided with the Exposure GoPro mount compatible holder as I often ride with a light mounted underneath my computer mount, given it reduces the chance of flare upwards and also centres the light facing forwards. While riding the light is so sleek and narrow that it was easy to forget that it was mounted underneath my bike computer.

The light fits into any of its mounting options with a simple press and it clips in. This is the same for all of the Sirius 11 mounts. As standard it is supplied with a mount that can be fitted to the handlebars, either below or above them. This is more difficult to use on aero bars or bars with a forward or backwards sweep, as it then directs the lights inwards or outwards. However for standard round bars it works well.

It actually has one significant benefit over the GoPro mount style option as well. When mounted under the stem, especially with exposed brake and gear cables, it can be a nightmare to try and actually press the single control button on the back of the Sirius. More often than not I needed to twist the light to get access to the button to switch the light on or change modes. With the handlebar mount, this is not really a problem.

Another issue however that I did face was the light twisting in its mount. The design of the light features a lip over the top so as to reduce flare, and when the light is angled down slightly it won’t shine into the eyes of other road users. However with the mount I found the light would twist throughout a ride to varying degrees, rendering the glare protector somewhat obsolete.

I also have mixed feelings around the single control button. You do a long press to select the mode, waiting for 1, 2 or 3 green light flashes to determine which control programme you are using. 1 being the highest power, 3 being the lowest power. Once a programme is selected, you have a full beam, dimmed beam, or daybright flash option to use. For non-changeable conditions I really like it. In daylight riding I always used mode 3 with the lowest power either on the flash or the high setting. However for days when it was a dark start of a long ride or fog rolled in, switching between programmes on the move is tricky and requires stopping. It is highly simple and effective, but not as versatile while on the move. Part of this is admittedly because I have exposed cables clustered just behind where the light mounts making the button more difficult to access. On a bike with internal cables this is far less of an issue.

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That is where my gripes end with this light though, mainly centred around the mount and button. After that, I have nothing but glowing comments.

I have an old Exposure light, a big bulky one from 2014 when I started cycling. It still had charge after not being used for more than 5 years, and still works well. This is more an example of the longevity of Exposure lights, and the quality of the lights and the support available in the UK remains exceptional. What was most impressive though is that old light was 800 lumens and a powerhouse on the road. The Sirius 11 is 1300 lumens in a far slimmer and smarter looking package.

On full power, the light battery does not last that long, but better than the old brick light did. It has an impressively long distance beam with a lux that illuminates the sides of the road well to highlight any holes or hazards. This is thanks to the 8° spot lens along with the 270˚ side visibility for a combination of range and blush. For pitch black riding down twisty country lanes, the Sirius 11 is sublime. You get around 1.5hr from this mode, even with 1 hour quoted, which is fine for most commutes back from work in the dark. Even with the lower power modes though the brightness is good enough for fast lane riding and the battery life jumps to 2 hours, but closer to 2.5 in my experience.

For adventures through the night, it’s not adequate, but with the USB-C charging port this light will work with power banks. Exposure recommends using a power bank with USB-C PD, which can output at least 18W, and the light can be used while charging whereas previously some only charge while off. This is limited to low output modes though while battery life is low, 4-hour modes or greater. This is due to the thermal build-up from charging while running the light simultaneously, and smart sensors in the light will dim if the heat gets too high. Charge time is fairly quick though, at just two hours.

To combat this heat buildup concern, the Exposure lights feature a machined aluminium body, which has greater heat dissipation properties than steel or titanium. At the front and rear, a more machined look with larger surface area is used to allow for even greater heat dissipation. On full beam, you can feel the light gets hot. Fortunately, the darkest days are also often the coldest, and travelling at speed the light cools down well.

Going back to the light itself though, the most common mode I have used this light in is the 400 lumen flash, which has a whopping 130hr claimed battery life. Given I went the entirety of December using this mode and did not need to charge the light once, the battery life indicator was still green, I believe the claims. IK09 impact resistance and IP67 water ingress standards mean I have had no issues with using this light on road, off-road, in the rain, or in groups where salted road spray has been jettisoned onto the light by wheels in front.

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Value

Exposure lights have a bit of a reputation of having some very expensive lights. £300+ is not uncommon, but machined aluminium bodies, a host of smart features, and impressive lumen outputs have somewhat warranted those costs over the years. In the Sirius 11, a lot of those smart features and power has been trickled down into a light package that is far smaller and more manageable, and at £120 is certainly not a light that breaks the bank compared to its bigger models.

The likes of the Knog Blinder 1300 is a bit cheaper at £99.99 and comes with a GoPro mount as standard, but features fewer modes and did recently get a product recall.

The Lezyne Lite Drive 1200+ is another close competitor with similar max brightness, slightly greater high beam run time, but lower total battery life at lower powers. It is also a fair chunk cheaper at £85. However I’ve seen reports that it is not as bright in reality and the beam less focussed for road riding.

My personal feeling around the Sirius 11 is that although it does represent a higher initial cost, the longevity of the lights Exposure makes from personal experience is a strong reason for investing in them. I have used plenty of good lights from other brands, but more often than not they don’t live up to the brightness or battery claims, and have yet to offer quite as sleek a solution to a front bike light or offer the speed of charging.

It’s not the cheapest light available, but what it offers overall I think is fair value in the short and long term.

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Verdict

The Exposure Sirius 11 light is an impressive performer. The LED used has an excellent spot beam range while the lux of the light has a great field of view providing strong visibility. Paired with that are a plentiful array of modes for most riding conditions with battery life from around 1.5hr up to 130 plus. DayBright is a great addition for those that want high visibility all year round, and the charge time is impressively quick for a light of this power and capacity.

It’s certainly not the cheapest light though, but that initial cost is also a longer term investment. The quality of the light is sublime, and previous experience with these lights and customer care is another highlight. The only actual area I would look to improve is how good the grip of the light mount is so it doesn’t twist while riding.