Whether you bike to work every day regardless of how dark it is outside, or only let dusk catch you on the occasional evening ride, every cyclist should have lights. They're required after dark by law in almost all regions, and are a crucial piece of safety equipment even where they're optional.
Remember that although spending $30-50 on good lights may seem like a lot of money, the medical costs from a single accident would far surpass that initial investment. If you bike at night (or even bike on busy roads during the day – several of these lights are daytime visible), a bright light is a must-have!
Choosing a light can be a difficult task though – there are countless options to choose from ranging from cheap $3 flashers to blindingly bright $200 powerhouses. The internet already has some good comparisons of bike headlights, but there's a surprising lack of comprehensive taillight comparisons, so I decided to make one. For science.
In total, I reviewed 16 different taillights from 8 of the top light manufacturers. I chose which lights to review based on a survey I conducted on the parent site for this blog - Bicycles Stack Exchange, a Q&A site for everything about bicycles, and also asked on Reddit's /r/bicycling. The incumbent in this race is the Planet Bike Blinky Superflash. Everyone has this light (myself included). Not only is it the light most people own, it's also the most-loved – 20% of respondents said it was their favorite. In terms of what people wish they had or are considering buying, the Planet Bike Superflash Turbo, Portland Design Works' Radbot 1000 and Danger Zone, and the Niterider Cherrybomb were all high on the list. Many people expressed an interest in DiNotte's lights, but unfortunately we were unable to acquire one for this review and the company declined to loan a light for the review.
I'm sure you're all dying to know which light is the best, but first, let's take a look at the contenders.
Top row (from left): Mars 4.0, Planet Bike Superflash Turbo, PB Blinky 7, PB Blinky Super Flash, Portland Design Works Red Planet, PB Blinky 5 Middle row (from right): Cateye Reflex, NiteRider Cherry Bomb, PDW Danger Zone, Cateye Rapid 3 Bottom row (from left): Knog Frog Strobe, Cateye Rapid 5, SE 6-way flasher Not pictured: Cygolite Hotshot, PDW Radbot 1000
The following statistics were recorded for each light. I will be writing a separate post with more details about the testing process. Cost (MSRP and online price) Brightness at 0, 45, and 90 degrees from the front of the light source, flash patterns, battery life, mounting mechanisms (default included & available separately), ease of installation, ease of battery replacement, and special features. (A note on brightness: this value was measured at a distance away from the light, using a mechanism to help capture some of the diffused light due to different lens and LED setups. The values are useful for comparing the brightness of the lights to each other, but should not be used as a comparison against any external sources, because measurement techniques and setup will be different.)
Each of these lights has its pros and cons, so how do they stack up against each other?
Brightness is one of the most important measures. The brighter the light, the more likely you are to be seen. Many LEDs give off a very focused, narrow beam, which makes it important to position the light carefully, and take into consideration brightness from other angles.
The graph above shows the relative brightness of each of the lights, using the value measured for straight-on brightness in the center of the beam. The Cygolite Hotshot far outshines everything else. The Blackburn Mars 4.0, Cateye Rapid 3, Planet Bike Super Flash Turbo, and Portland Design Works Radbot 1000 are all similarly bright lights near the top of the remaining lights.
So, of these lights in the 10,000+ club, what other factors should we consider? It's worth noting that the Rapid 3, although bright, has a very limited battery life (it runs off a single AA cell, instead of dual AAA cells like most lights). The Mars 4.0 has a slow blink pattern, which isn't as attention-grabbing as some of the other choices. The Super Flash Turbo and Radbot 1000 are similar in many ways. The Turbo is slightly brighter when flashing, but the Radbot is actually brighter in solid-on mode. I prefer the Radbot for its more varied flash patterns, extra mounting options included, and superior on/off switch. The Radbot is also cheaper.
If you're looking for the brightest light, the Hotshot is definitely your best bet, and if you purchase it online, can be found for less than the cost of the Super Flash Turbo. If you like being able to replace the batteries on the road, or need a more robust mount though, the Radbot 1000 is a great light as well.
The brightness-per-cost graph shows the relationship between the maximum measured brightness and the online prices listed at the time of this writing. Higher means brighter; further right means more expensive. The best deals will be lights high up and towards the left.
The Cygolite Hotshot is high up on the chart, and on the slightly more expensive side (though not the most expensive). The Mars 4.0 is one of the best deals, at exactly $20 and high in the brightness scale. A few lights stand out as being a bad deal in the brightness vs. cost arena: the Reflex Auto costs as much as a hotshot, and is very dim. It appears that the venerable Blinky Super Flash (not to be confused with the Super Flash Turbo, which is expensive but also pretty bright) is also no longer a great value for its price: it's more expensive and dimmer than several of the other choices.
With the cost of batteries (not to mention the environmental impact of non-rechargeables), it's important to consider how long your light will last. For the battery tests, I set the lights to flashing mode, and checked on them approximately every 5 hours. I made a qualitative assessment of whether the light was still bright, had started to dim, or was nearly dead ("weak").
Surprisingly, a few of the lights lasted a week before dying out. The Cygolite Hotshot was again the champion, going 120 hours before even starting to drop in brightness. This is almost certainly thanks to its built-in lithium battery, with a much higher capacity than typical alkaline batteries.
In general though, brighter lights tended not to last as long (unsurprisingly). The Cateye Rapid 3 was the first to die, lasting only 20 hours before becoming almost useless. If it had been designed to be slightly larger and use 2 batteries instead of one, it may have fared better. The Frog Strobe was one of the worst in this category, lasting only 34 hours on its puny CR2032 batteries.
Each of the lights reviewed has its own pros and cons, and there are a lot to choose from. Below are the best in three categories: Editor's Picks are the ones which struck my fancy, Best Value are those with the best features for the lowest price, and the Grand Master is the best light overall.
• PDW Danger Zone: Although it's a bit pricey, has annoying battery replacement, and is not really the best deal, I took a real liking to the Danger Zone. It's the only light with dual high-intensity LEDs, has eye-grabbing flash patterns, and seems pretty sturdy overall. (Full review)
• Planet Bike Superflash Turbo: Also rather pricey, but the Turbo is a nice evolution of the original PB Super Flash we all know and love. It's incredibly bright, seems a bit sturdier than the old Super Flash, and works with any existing PB mounts. (Full review)
• Blackburn Mars 4.0: At only $20 online ($25 MSRP), the Mars 4.0 is in the middle of the price spectrum, but is one of the brightest lights. I wish its flash pattern were a little more exciting, and the mounts are a bit fidgety, but if you're on a budget, this is one of the best choices at this price point. (Full review)
• SE 6-Way Flasher: It's actually a pretty wimpy light (it was the 2nd dimmest), but because it only costs $4, its brightness-per-dollar ratio is incredibly high. The batteries also last a long time. If you bike at night with any frequency, this probably isn't a good choice, but hey – you could buy 3 of them and mount them in different places for the cost of a single Knog Frog, which is even dimmer. If you're really tight for cash, or only bike at night very rarely, this may be a decent choice, but you should probably get something brighter. (Full review)
• Cygolite Hotshot: In all of the categories of data measured, the Hotshot prevailed. It's the brightest, has the longest-lasting battery, has the most flash pattern options (which you can even configure yourself), and at $27 online ($40 MSRP) is even cheaper than a lot of the dimmer competition. Of course, it's not without its flaws – the plastic mounting mechanism is terrible, and the control buttons aren't easy to work with. Nevertheless, those minor downsides are far outranked by this light's superb performance. I can see its reflection as far back as there are reflective surfaces in a line of sight. In case you missed it, I gave it a very detailed review above. I highly recommend this light for just about anyone.
There are a lot of factors that go into choosing a good light. I've tried to explore most of them as well as I could here, but each cyclist will have his or her own needs and preferences. There are a few important things to keep in mind regardless of which light you choose:
• Positioning : It doesn't matter how bright your light is if it's aimed at the ground or the sky. Especially with LED lights, the most intense beam tends to be very focused. Make sure to mount your light carefully so that it's facing towards the level a driver would see from, but just slightly above or below so as to not entirely blind them. As a good check, have a friend get on your bike, and then go sit in a car behind them and see how well you show up.
• Flashing vs. solid: There's debate over whether a flashing or solid light is better for your safety. In some jurisdictions, flashing lights aren't permitted; in others, they're required. According to a very detailed answer on our site, research done by engineers at RPI (PDF) has shown that flashing lights are perceived as brighter, while solid lights make it easier to determine an object's location. It's therefore advisable to have both a solid and a flashing light. I would advise getting a bright (1W or brighter) light to use in flashing mode, and having a second cheaper light to run in solid mode. Using solid-light mode uses batteries faster than flashing (because the light is on all of the time instead of only intermittently), so a less-bright solid light may last about as long as a very bright flashing light. Paired together, you will get good visibility (from the flasher) but also make it easier for motorists to gauge your distance (with the solid light). The same study also noted that having multiple lights positioned in different places helps drivers gauge distance and position better as well.
• Theft: bike lights are an easy target for thieves looking for something to quickly steal and sell. It always shocks me to see just how many bike lights could be easily grabbed from bikes which are otherwise locked up well, and I know many people who've had theirs stolen. Make sure to either take your lights with you, or use a mount which locks them in (like the rack mount for Cateye lights).
Excerpted with permission from the Bicycles Community at Stack Exchange. For more details about each of the lights, check out the full review.
Top Image via pio3/Shutterstock.com