The Sigma Buster RL 150 Rear Brake Light is a great option at a very reasonable price. With an automatic brake light function and a maximum output of 150 lumens on its day flash setting, it’ll help you feel safe and seen, whether you’re using it for commuting at night or training during the day.
The light comes with a silicone strap already attached – the light itself is the bracket, it’s just a one-piece design – so you don’t have to worry about extra parts that could break or get lost. It’s very easy to attach to the bike, and if the strap isn’t long enough for your seatpost you can buy an extended version.
The back of the light is curved to suit the contour of the tube, which helps keep the light in place even over the bumpiest of roads – thank you potholes! Also, the angle it sits at is optimal: facing level out to other road users and pedestrians behind me to ensure it’s visible for all.
The on/off button is located clearly on the top of the light, and changes the modes as well as doubling up as the battery life indicator. It’s really easy to use and not fiddly at all.
Those modes are: constant high (40 lumens), constant low (5lm), day flashing (150lm), night flashing (25lm) and eco flashing (5lm). To change modes requires just one click – no confusing double clicking like some.
I was also surprised to find out that I didn’t need to do anything at all to set up the brake light function. This just comes on automatically when in use, thanks to a built-in decelerator that detects when you and your bike are slowing down. Simply attach the light, turn on, select your setting, and go.
Charging
The included USB-C cable fits into a port on the underside of the light, hidden behind a thick rubber flap that is very well fitted to keep debris and water out. The flap fits into a small indentation in the light, with a little flap of rubber to make accessing the port easy. Little well-thought-out features like this are great.
A full charge took around three hours, and LEDs indicate the level of charge and how far along the process the light is: green is 100%-40%, orange is 39%-20%, red is 19%-5% and flashing red is less than 5%.
Performance
I was very impressed with how visible this light is; it’s very bright, be it in daylight or complete darkness.
A feature that performed better than expected was the automatic brake light, which is brilliant and really made me feel safer when out on the road. I was skeptical at first, but I’m definitely converted.
Run-times are pretty good, too. Over the course of some long rides, and leaving the light on once home, battery life tallied with the claimed four hours for high constant and six hours for day flashing, though ideally I’d like a longer run-time on the latter, which is the setting I use most and the one I’d choose when I’m out doing very long rides. For many, though, I imagine this battery life is completely adequate.
Having an indication of when the light might die and what percentage the battery is at, thanks to the LED lights on the on/off button, is a welcome feature: no more panicking wondering if it’ll last long enough.
Value
With a price of £29.99 this isn’t the cheapest rear light on the market – there are more budget-friendly options, such as the Knog Plus Rear Light, now £18.99 – but given features such as the brake light and 150-lumen day flash, it’s pretty good value.
It’s the same RRP as the Magicshine Seemee 100, which also has a built-in brake light function, but that only produces a maximum of 100 lumens. And the Seemee 180 – max output 180lm – is £34.99 (though currently reduced to £29.99).
I’ve been using the Moon Nebula Rechargeable Rear Bike Light, which has a brighter 200-lumen flash – but that’s £44.99, doesn’t include a braking function and the battery only lasts for one hour on the brightest full setting, whereas the Buster RL 150 lasts for around four hours.
For more options, check out our guide to the best rear bike lights.
Overall
From the off I was impressed by this light. It’s a well-thought-out piece of kit – easy to use, the brake light feature doesn’t require any complicated setting up, and though I would like a longer battery life on day flashing for long day rides and bikepacking, for commuting you shouldn’t have any issues on one full charge.
Verdict
Bright, simple to use, and well priced, a great rear light to keep you feeling safe and seen
All the deals displayed on our review pages are pulled from a constantly updating database feed of the best affiliate deals available. The criteria for deciding on what are the best deals is who is offering the lowest, delivered price. In most cases we will be showing the very best deal available online, but sometimes you may be able to find an item cheaper. If you can please feel free to post a link in the comments box below. To find out more about affiliate links on road.cc click here.
road.cc test report
Make and model: Sigma Buster RL 150 Rear Brake Light
Size tested: 150 lumens
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?
Sigma states: “The BUSTER RL 150 ensures that no one will ever overlook you! Its 150 lumens and visibility range of 2,000 meters offer maximum visibility. Everyone will know where you are. The practical brake light function warns everyone if you have to brake suddenly. Five light modes, including flashing modes, are available. This gives you up to 20 hours of light. Durable, robust, and mounted without tools – the perfect rear light for the toughest requirements.
“The BUSTER RL 150 allows you to react flexibly to the various requirements of weather and lighting conditions. High and Low mode and three flashing modes are available to you. Full power on a night ride or economical operation on long tours – no problem for the powerful SIGMA rear light.”
Tell us some more about the technical aspects of the light?
From Sigma:
BRAKE LIGHT FOR MORE SAFETY
The integrated acceleration sensor ensures that the BUSTER RL 150 knows right away when you brake. The two LEDs light up especially bright for about three seconds. This cool feature ensures more safety – not only at night, but also during daytime rides in road traffic or during a group tour.
FLASH MODES FOR MORE SAFETY
The BUSTER RL 150 is equipped with three additional flash modes that make your ride even safer, day and night. The Day Flash with its two pulsing red LEDs lasts for 6 hours, drawing attention to the cyclist. In Night Flashing mode, the USB rear light can continue flashing for up to seven hours. For longer rides, the Eco Flash mode provides additional visibility in road traffic for 20 hours.
CONVENIENT MEMORY MODE
The memory function ensures that the BUSTER RL 150 always switches back on in the mode that it was in when it was switched off. This practical feature makes it easy for anyone to get started quickly.
MORE SAFETY THANKS TO LATERAL VISIBILITY
The BUSTER RL 150 is equipped with side apertures that ensure that the light can be seen at an angle of 280 degrees. This is lateral visibility an important safety feature, especially in city traffic.
POWERFUL WITH AN ENVIRONMENTALLY-FRIENDLY BATTERY
Never change batteries again with the BUSTER RL 150 – the long-lasting, powerful lithium ion battery keeps your cycling sustainable. The USB-C port can be used to charge the light completely within three hours.
THREE-LEVEL BATTERY INDICATOR
A short press on the operating button shows you how much power your BUSTER RL 150 still has. This enables you to switch to a more power-conserving lighting mode if you need to. The battery indicator has three levels. This gives you confidence at all times that you have enough power to get back home.
THE ALL-WEATHER LIGHT
The BUSTER RL 150 is resistant to splashing water in accordance with the international IPX4 standard, so it can handle a downpour with no problem. The battery-powered rear light is a reliable companion in all kinds of weather.
Super user friendly, and the added feature of the brake light is great.
Having five different loops to choose from, with the silicone fastener, ensures the light fits different sizes of seatpost securely while riding.
It’s IPX4 rated, which isn’t that high, but for the cost of the light it’s not bad. I went out in Storm Bert’s torrential rain and the light had no issues whatsoever.
Over the course of some long rides and leaving the light on once home, I found the estimated battery life claimed by Sigma – four hours for high constant and six hours for day flashing – was roughly accurate for the different settings.
Pretty average, but not something I really care about regarding a rear light: a really small one may be lighter but less surface area for the light, so overall not practical. It’s not an important aspect in my experience.
Pretty good compared with other rear lights with a brake light function.
Tell us how the light performed overall when used for its designed purpose
I found this light really impressive. It’s nice and bright, and helped me to feel safe riding on low-light days or in the dark. The automatic brake function also worked really well and is a feature I was particularly surprised by. There are also plenty of modes to choose from to suit different riding needs.
Tell us what you particularly liked about the light
I really liked the automatic brake light function, as well as all the different modes.
Tell us what you particularly disliked about the light
Although not a dislike, per se, a longer battery life on constant would be great.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
It’s by no means the cheapest rear light on the market – there are more budget-friendly options, such as the Knog Plus Rear Light, now £18.99 – but given features such as the brake light and 150-lumen day flash, it’s pretty good value.
It’s the same RRP as the Magicshine Seemee 100, which also has a built-in brake light function, but that only produces a maximum of 100 lumens. And the Seemee 180 – max output 180lm – is £34.99 (though currently reduced to £29.99).
I’ve been using the Moon Nebula Rechargeable Rear Bike Light, which has a brighter 200-lumen flash – but that’s £44.99, doesn’t include a braking function and the battery only lasts for one hour on the brightest full setting, whereas the Buster RL 150 lasts for around four hours.
Did you enjoy using the light? Yes
Would you consider buying the light? Yes
Would you recommend the light to a friend? Yes
Use this box to explain your overall score
From the off I was impressed by this light. The automatic brake light itself is a great feature and helped me to feel safer when out riding on the road. And in the dark I felt the light was particularly impressive: even on the lower settings it’s very bright. Add the fast charging and good battery life and overall it’s very good.
About the tester
Age: 25 Height: 173cm Weight: 65kg
I usually ride: Road bike My best bike is: Road bike
I’ve been riding for: Over 20 years I ride: Most days I would class myself as: Semi pro
I regularly do the following types of riding: road racing, general fitness riding, fixed/singlespeed, mtb,
