The Best Rear Bike Lights (Review & Buying Guide) in 2021
Stay visible, stay safe, and stay cool with rear bike lights.
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BY Brian Smyth / LAST UPDATED ON March 5, 2021
Anyone who rides a bike regularly knows that easily the biggest hazard on the road or trail is other people. On the road, drivers often fail to pay attention to those on two wheels instead of four. More than motorcycles, bicycles appear and disappear from view extremely quickly due to their small profile. Without a rider's concerted effort, many drivers will simply not see them without a good rear bike light.
These lights increase a bike's visibility, keeping riders safe and drivers more aware. On the flip side, off-road bikers can benefit from a quality rear bike light as well. Visibility translates to safety when fellow bikers and other trail adventurers can see you coming, especially when it's dark. If you're interested in finding the best rear bike lights, we've compiled a list of the top options available.
The Guard G3X Pro100 gives bikers a bright tail light with safety-conscious strobe and flash patterns, and its long, narrow body fits neatly behind any bike’s seat post.
- Puts out 100 lumens
- Has a visibility arc of 180 degrees
- Holds an IPX5 rating
- Brand has good customer service
- Some users have seen limited longevity from their lights
- Minimalist mounting strap
The Pyro Bike Light Set keeps bikers safe in daylight and low-light settings, providing them with both front and rear running lights at an excellent price point.
- Both lights put out 80 lumens
- Each light has a built-in clip for easy attachment to other objects
- Built with aluminum
- Only has an IPX4 rating, limiting its water resistance
- Front light is only bright enough for daylight running and will not work as a headlight
The Varia RTL510 provides bikers with a “just right” rear running light, and its radar system does what Garmin does best: using modern technology to enhance safety and convenience.
- On high, the light puts out 69 lumens
- Holds an IPX7 rating
- Rear-facing car detection radar works as an electronic rearview mirror
- Integrates with Garmin GPS units
- Very expensive
- Lumen output on low settings is too poor for daytime use
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Benefits of Rear Bike Lights
- Safety. Rear bike lights bring attention to bikes and their riders, increasing their visual profile. A better profile turns bikers into a focal point, raising the situational awareness of other people on the road or trail. In turn, bikers, drivers, and pedestrians can avoid dangerous and costly accidents.
- Easier group travel. Traveling in a group can be a challenge, particularly in poor weather or environments with bad visibility. When each member has a light on their bike, keeping the group together without collisions becomes a much simpler chore.
Types of Rear Bike Lights
Today, the vast majority of bicycle lights are powered by either disposable or rechargeable batteries. These lights are simple and convenient, requiring no parts beyond the mounting component(s) and the light itself. As such, they can be mounted in multiple locations, making them extremely convenient to use.
Of course, batteries must either be replaced or recharged to keep these lights working. Many lights now use USB-based rechargeable batteries, although those who prefer traditional alkaline-style batteries can still pick one up.
While rare in today’s market, there are alternatives to using battery-powered rear bike lights. Those wishing to generate their own electricity can find a dynamo light instead, using tire revolutions to create an alternating electrical current to generate the light’s electricity.
The additional parts and electric cables can be a bit of an obstacle for some, and when the bike slows down, the light begins to dim. Still, this is a very eco-friendly alternative to disposable batteries and mining-intensive rechargeable batteries.
In 1991, a group of bike-loving engineers launched Cygolite in Irvine, Calif. The company’s first product was an LED blinking tail light, a predecessor to current offerings like the Cygolite Hotshot Pro 200. Today, the company focuses on creating LED-powered, USB-rechargeable bike lights.
Knog first saw the light of day in 2002, thanks to Hugo Davidson and Mal McKechnie. Based out of Melbourne, Australia, the company focuses on producing handheld lighting systems like headlamps and flashlights and bike accessories like bike lights and bike bells.
German native Micki Kozuschek founded Lezyne on March 1, 2007, at the top of his career as a professional triathlete. Headquartered in Reno, Nev., the company specializes in bicycle tools and accessories, including pumps, multitools, GPS devices, and lights.
In November 1996, Planet Bike first arrived on the biking scene in Madison, Wis. From the beginning, this cycle-centric company has focused on producing top-tier bike apparel and gear of virtually every type, such as the Planet Bike Grateful Red Bike Tail Light.
Rear Bike Light Pricing
- Under $50: Lights in this price range usually max out around 100 lumens, with many lights putting out lower numbers. IP ratings for water resistance are usually around IPX4 or IPX5.
- $50 and up: These lights tend to have lumen outputs at or above 100, with some reaching the 300-lumen mark. These lights are much more likely to earn an IP rating of IPX7.
Lumen output is one of the essential features of any rear bike light. These lights help keep bikes and their riders visible to traffic approaching from the rear, so a light that is too dim lacks practical value. For daytime rides, use a light rated for at least 50 lumens as the sun will drown out lights with lower outputs.
The human eye is most attracted to green lights and movements, so the small red light on a relatively slow-moving bike may fail to catch a driver’s attention. As such, a rear bike light with a strobing or flashing pattern and a bright enough output help pick up the slack, grabbing an approaching driver’s attention much faster than a solid, dim bike light.
A bright, strobing light means nothing if it cannot withstand the weather. Lights from reputable manufacturers will feature an Ingress Protection (IP) rating. Most units will feature a rating between IPX4 and IPX7. Units rated IPX4 are only splash resistant, while IPX7 units may be temporarily submerged in up to three feet of water. IP ratings with a number in place of the “X” have been tested for resistance to intrusion by dust and debris.
Make sure to purchase a rear bike light with the battery life to support applicable ride times. Most lights have a runtime range that will account for low-output settings and high-output settings. While some lights may run for only a couple of hours on their highest setting, a few will hit over 75 hours of runtime on their most battery-friendly setting.
- Mounting Options. Light mounting options vary from unit to unit, but many are available with a strap-based mounting system for easy adjustments and removal since most of these lights are rechargeable via USB. A few tail lights still feature traditional hardpoint mounting systems with a clip-on feature, fixing the light at a given angle while still allowing users to easily remove it when necessary. Some lights feature a hybrid system, combining the best of both approaches.
Best Rear Bike Lights Reviews & Recommendations 2021
- Before purchasing a rear bike light, consider the worst possible lighting and visibility conditions you might encounter to determine the appropriate lumen output.
- When purchasing a rechargeable light, be sure to get a battery with at least twice the life you anticipate needing. Otherwise, find one that runs while charging and buy a bike-mountable solar charger to match.
- Bikers with traditional battery-operated should pack along extra batteries in a waterproof or extremely water-resistant container.
Q: How bright should my rear bike light be?
Rear bike lights should be bright enough to make them visible in any weather or lighting condition; this usually requires an output of at least 50 lumens. Since bike lights are much smaller and less noticeable than car lights, purchase one with an eye-catching flash or strobe pattern.
Q: What is the ideal number of lumens for a rear bike light to ensure I'm visible on the road?
A rear bike light with an output of at least 50 lumens should provide adequate visibility in most weather conditions, both day and night.
Q: Should I use a rear bike light during the day?
On-road bikers should consider using a rear light during the day. A proper light will put out at least 50 lumens and have an eye-catching strobe or flashing pattern.
The 100-lumen Apace Vision Guard G3X Pro100 enhances in all conditions while saving bikers’ money. On the other hand, the Vont Pyro Bike Light Set provides 80-lumen running lights for both a bike’s front and rear, all at less than the cost of most single-light options.