A good rear bike light should be bright, dependable and require very little attention. Ideally, it should also survive the sort of weather that makes you question why you didn't take the car. The Exposure Lights TraceR 4 ticks those boxes rather nicely, combining powerful daytime visibility, an impressively long battery life and rugged British engineering in a compact 38g package. It's the kind of little cycling accessory that quietly gets on with an important job, even when the rest of your commute isn't going quite to plan.
The TraceR 4 delivers up to 200 lumens through Exposure's distinctive DayBright pulse, designed to help you stand out in bright daylight as well as darker conditions. Its clever 270° Commute Lens spreads illumination around the sides of the light, providing additional visibility at junctions where approaching traffic isn't always directly behind you. A rechargeable battery delivers up to 40 hours of runtime, while USB-C charging gets you back to full power in approximately 90 minutes. Add a CNC-machined aluminium housing, IP67 weather protection and a useful battery status indicator, and you've got a seriously well-equipped little rear light. Small enough to forget it's there, bright enough that everyone else has a better chance of noticing.
Key Features
200 Lumens Maximum DayBright Output – Powerful daytime pulse helps improve visibility to approaching road users in bright conditions
Exposure DayBright Technology – Distinctive flashing pattern is designed to stand out more effectively than a conventional steady pulse
Over 1km Daytime Visibility – Manufacturer-rated DayBright visibility from over a kilometre away under suitable conditions
270° Commute Lens – Wide-angle optical design provides excellent side visibility as well as rearward illumination
Enhanced Junction Visibility – Extended side illumination helps make the rider more noticeable to traffic approaching from different angles
Up To 40 Hours Runtime – Long battery endurance supports regular commuting and extended cycling adventures
USB-C Rechargeable Battery – Convenient modern charging connection makes keeping the light powered straightforward
90-Minute Charging Time – Fast charging helps minimise downtime between rides
38g Lightweight Construction – Compact, unobtrusive design adds minimal weight to your bike
CNC-Machined 6063 Aluminium Body – Precision-engineered aluminium housing provides durability and a robust everyday finish
Scratch-Resistant Polycarbonate Lens – Tough front lens helps withstand everyday knocks and general road use
IP67 Water & Dust Resistance – Sealed construction protects against dust ingress and temporary immersion under specified test conditions
Five-Second Battery Status Display – Check the remaining battery level with a single button press while the light is switched off
Automatic Shutdown Battery Indication – Battery status is also displayed when switching the light off
Compact Rear Light Design – Slim, practical construction keeps your seatpost setup clean and uncluttered
Seatpost Bracket Included – Supplied mounting bracket provides a secure fitting for compatible seatposts
Simple Button Operation – Straightforward controls make switching between supported lighting modes easy
Integrated Rechargeable Design – Self-contained battery eliminates the need for disposable batteries or external power cables during use
Weather-Resistant Commuting Performance – Designed to cope with rain, road spray and demanding year-round cycling conditions
British Lighting Engineering – Developed by Exposure Lights with an emphasis on durability, practical functionality and dependable performance
The Exposure TraceR 4 is proof that a rear light doesn't need to be enormous to make a meaningful difference to your riding setup. Its powerful DayBright pulse helps you stand out during the day, while the 270° lens provides useful visibility from the sides. The long runtime and quick USB-C charging make everyday ownership refreshingly straightforward, and the tough aluminium construction is ready for the realities of British weather. It's one of those accessories you fit, charge occasionally and get on with using. Which is exactly how a good bike light should behave.