Way back in 2012 when I did my first bike taillight roundup, I picked up a Cygolite Hotshot after somebody suggested I check it out. It was one of the first all-in-one USB-rechargeable taillights to become available, and handily won the title of "best taillight" in comparison to the now-archaic AAA-powered lights which dominated the market at the time. Fast-forward four years and while the original Hotshot is still much-loved by cyclists, the age of its internal electronics was starting to show. The new Hotshot series launched last fall keeps everything we know and love from the original Hotshot while boosting performance and adding new features.

This review is of the Hotshot Pro 80, but the nearly-identical Hotshot 100 is now available, as well as the Hotshot 150 with a slightly modified design.

Complaints about blinding glare are increasingly common as bike lights get brighter and brighter. Getting 1000 lumens directly to the face is never fun, and yet most bike lights on the market today have circular beams which direct as much of the light towards oncoming people as they do towards the road. Not only is this a safety hazard and inconsiderate towards other road users, it's also a waste of light... if you weren't shining half your light into the trees and other people's eyes, your light wouldn't use as much power.

Enter the Busch & Müller Ixon series. B&M is a leader in dynamo lighting, and their dynamo lights are widely recognized for having expertly crafted lenses which focus the light on the road and only on the road. Their battery-powered solutions aren't as well known, and were previously all bulky and rather unsightly products. The new Ixon Core series changes that. The series was recently refreshed with the addition of the Ixon Core Flash, a sleek, modern, rechargeable headlight which is as nice to look at as it is to see with.

Cygolite's Metro series is widely recognized as a leader in affordable and high-quality commuting headlights. I first reviewed the Metro 300 back in 2011, and have been a fan of the lights ever since. Five years later, the Metro looks identical from the outside – same shape, size, and weight – but Cygolite is pushing the technology inside to perform at new levels. The Metro 750 puts out up to 750 lumens, has different flash options optimized for daytime and nighttime, and is the company's first commuter headlight to implement their "enhanced cycling optics" for a smoother and better shaped beam. If you've used and enjoyed previous Metro lights and are looking for an upgrade, you'll like the Metro 750. If you're looking for more info, read on to get the full story.

Beam Output and Flash Patterns

The Metro 750 is the first (and currently only) light in the series to have what Cygolite calls its "enhanced cycling optics". It's a fancy name for a simple solution: adding a diffusing lens to the beam. Most lights have a symmetrical circular beam, meaning as much light gets shined into the sky as onto the ground. A diffusing beam widens and flattens the beam shape, making it more rectangular instead of circular. This uses the LED's output more efficiently, lighting up a wider path and reducing glare into the eyes of oncoming people.

Rapidly-improving LED technology has brought us brighter bike lights, and lithium batteries have brought us easy charging, but the #1 complaint I hear from people considering a new bike light is the inability to replace the batteries in modern rechargeable lights. Most of these lights are a sealed package, much like smartphones which aren't designed to be opened up. Whether the battery runs out during a long ride or just can't keep a charge after years of use, there are legitimate concerns over the practicality and environmental impact of single-piece rechargeable lights.

Enter Fenix. Best known as a cost-effective high-performance flashlight company, they've been gradually increasing their array of bike light options over the past few years. I reviewed the BC30 this fall, their first single-piece bike light with user-accessible standard-sized 18650 lithium batteries. The BC30 had a few shortcomings though: the batteries must be removed to be charged, both batteries and a charger must be purchased separately from the light, and it's a pricey light once you add in all those extra purchases. It's also overkill for most riders — at 1200 lumens and with two batteries, it's more appropriate for hardcore trail riding than urban commuting.

The Volt 100 and 200 are Cateye's low-cost entry-level headlights, primarily designed for safety visibility rather than lighting up a dark path. Cateye sent me a Volt 100 to test this fall, as the Volt 200 wasn't available yet at the time. Although its output is much lower than the many high-powered headlights which are quickly approaching car headlight outputs, the Volt 100 is a good option for riders on a budget who primarily ride on lit urban streets, or weight-conscious road bikers looking for a light-weight backup for long rides that stretch into the evening.

Although advertised as putting out 100 lumens, the Volt 100 was actually measured at 160 lumens on high by MTBR. My own runtime testing shows that the output is reasonably well regulated, with the light remaining above 80% of its initial output through the first hour, maintaining 75% after the claimed 2 hour battery life, and finally dropping into flashing mode after 2:25 hours. The internal lithium battery is easily recharged by a micro USB port which supports fast chargers.

Cateye's Rapid series offers a variety of lights designed for safety visibility, including their full taillight lineup. The Rapid X2, which we reviewed in October, is the high end option, offering a 50 lm output and six flash patterns. The Rapid Mini is a new product targeting the low-cost and light-weight market. It weighs just 22g, vs. 31g for the Rapid X2. It sports a 3 hour battery life in constant mode at 15 lumens, and lasts up to 30 hours in flashing mode.

While many of the taillights being released these days are designed for daylight visibility and more extended runtimes, the Rapid Mini is really only useful for nighttime riding. I would be hesitant to use it as my only light while riding on high-speed streets with lots of motorized traffic, but if you're mostly riding on slower streets and don't want to break the bank, it'll do the job.

The Fenix BC30, which we recently reviewed, is a great choice for anybody wanting the best in battery flexibility. Whereas the BC30 uses two 18650 batteries which the user must provide and charge themselves, its fraternal twin the BC30R has batteries built in and uses USB charging. The BC30R also offers a nifty OLED battery life meter, similar to those found in the MagicShine Eagle 600 and the NiteRider Lumina 800 OLED. For riders who want a light with great output and a long battery life, but don’t want the hassle of dealing with rechargeable batteries themselves, the BC30R is a strong choice.

Screen and controls

The most noticeable distinct feature of the BC30R is its large OLED screen which displays the remaining battery life. The system is simple and easy to use. There are three buttons on the top of the light – a main power button, a (+) button, and a (-) button. As you might expect, the (+) and (-) increase and decrease the light's output. This is great because you don't need to cycle through all of the modes to switch between a higher and lower setting. As you switch modes, the OLED screen displays "Level n" in the lower corner. Within a few seconds of switching modes, the screen will update to show the estimated runtime remaining. The OLED screen is backlit, so you can see it at night. The backlight brightens when you push a button and dims again after a few seconds to preserve battery life and not be distracting. The display only shows a time estimate; as far as I know there is no way to display a percentage value. Fortunately, the time estimate seems to be very precise, which will be discussed more in the battery section below.

Fenix is a popular manufacturer of high-powered and reliable flashlights. The company has recently started producing lights specifically designed for biking, but with designs heavily influenced by the prosumer flashlight market. The BC30 is a single piece light containing two 18650 lithium batteries and two Cree LEDs. These form a "dual distance" optic which combines a flood and throw pattern. The light is advertised as an 1800 lm light, but the maximum sustained output is only 1200 lm. A remote switch is included which boosts the output to 1800 lm when the button is depressed. The BC30 is large and heavy, but offers a level of flexibility not found in many other headlights. Read on for an introduction to modern rechargeable batteries, or if you're already an 18650 fan, skip to the full review of the light.

Cateye Volt 700

Cateye's rechargeable headlight series, the Volt, has been around for a few years now. After receiving several requests to review these lights, I’m excited to finally have one in hand. The Volt 700 is the top-end model; a review of the entry-level Volt 100 is also on its way. This light stands out from the crowd, featuring a removable USB-rechargeable battery which can be charged even when not attached to the light, and enhanced optics to spread the light evenly over the road.

Output and Visibility

At full power the Volt 700 is bright enough for almost any type of riding, including nighttime trail riding. For rides in the city where some street lighting is present the medium or even low modes are enough to illuminate potholes and debris when traveling at a moderate speed. Cateye's "opticube" lens creates a rectangular beam, spreading the light out across the path in front of you and reducing the amount of light wasted illuminating the sky above you. It doesn’t have a sharp beam cutoff, so you should still be mindful of how you aim it to avoid blinding oncoming traffic. A small side cutout gives some off-axis visibility, although not nearly as much as lights with full side lighting like the Bontrager Ion 700 and the L&M Urban.

The original Cateye Rapid X did not impress me – its small size and weight necessitated weak output and a very short battery life, and the rubber band mount was difficult to use and keep track of. The new Rapid X2 is a significant improvement in many ways. The output has been increased from 15 to 50 lumens, making the light bright and visible, day and night. Unfortunately the mount is still problematic, but for certain applications the Rapid X2 is a strong choice for a taillight. Read on for the full review.

Output, visibility, and flash patterns

The Rapid series has always offered a wide range of flash patterns. With 6 different modes it’s a bit much to choose from, but there’s a good mode for almost any situation. A low-brightness steady burn mode and a subtle pulsing mode are both good options to prevent blinding other cyclists nearby. The rapid flashing mode and the fast flashing mode are great for visibility in busy traffic, and are attention-grabbing even in broad daylight. The light remembers the last mode used. A single press of the button cycles through the pattern options and a long press turns the light on or off.

Bontrager recently entered the high-powered bike light market with a bang – their Ion 700R headlight quickly made its way to our top headlights recommendations list for its sleek design, nice optics, good mount, and excellent value. The Flare R is Bontrager's first attempt at a modern taillight, and features many of the same well thought-out designs that were introduced with the Ion. The competition is tough though, especially for a $60 light, so let's see how the Flare fares.

Optics and visibility

First, to clear up any confusion: Bontrager advertises the Flare as being a 65 lumen light, but that's only in the highest daytime flash mode. The steady-high mode only puts out 25 lumens, putting it on par with lights like the Cygolite Hotshot. To be clear, 25 lumens is not bad for a steady mode, especially at night, but the prominence of the "65 lumen" advertising feels slightly misleading. We'll get to the details of those flash modes in a moment.

Nobody likes being blinded when riding or driving at night, and as bike light LEDs get brighter and brighter, this is increasingly a concern for road users of all types. Most bike lights, even those costing hundreds of dollars, have symmetrical beams which shine equal amounts of light above and below the device. The result is that significant light is wasted by shining far above where the rider needs to see, and as a side effect, the glare can disorient oncoming traffic.

Most dynamo lights conform to strict standards which require a horizontal beam cutoff, but few single-piece battery-powered lights do, especially those costing less than several hundred dollars. Cycle Torch's new Shark 500 light seeks to change that, introducing a low-cost light with a horizontal beam cutoff to prevent distracting other road users. Read the full review to find out how well it works.

It's difficult to review this light because there are so many different variations. I purchased the unit I reviewed on Amazon from a vendor which no longer even exists, but dozens of others have popped up to take its place. And that is the very issue with these lights: you never quite know what you're getting. They all look the same, are all made by generic manufacturers in cheap Chinese factories, and none of them have a reputable company backing up the product. You could order 10 of these lights from 10 different vendors and get different performance, build quality, and longevity – and there's no way to tell how good a particular light will be until it shows up.

Updated August 2015 with information about battery safety. NOTE: This product may be dangerous! For safety reasons we do not recommend purchasing generic lights from unreliable manufacturers.

Most cyclists will recognize Bontrager, or at least its parent company Trek – one of the largest bicycle companies in the world. Bontrager has been selling some very basic lights for years, but the company is hardly well-known as a lighting company. That's why I was so pleasantly surprised when I started using the Ion 700 they offered to send me. It gets almost everything just right, and is one of the most impressive first attempts at a high-power single-piece rechargeable light I've ever seen.

The first thing I noticed is that the Ion 700 is compact. It's narrower than many comparable lights, with a sleek and clean design. The low-profile mount keeps the light just barely above the handlebars. It's operated by a single button on the top, and has a USB micro port on the bottom for charging.

Planet Bike was among the first popular vendors of LED bike headlights, and its Blaze 1W and 2W lights were once very common among bike commuters. The industry has progressed quickly though, and for many years Planet Bike was falling behind with no high-intensity or rechargeable LED offerings. With the debut of the Blaze XLR, Planet Bike has finally released a bright rechargeable light, and it has a lot to offer.

Light output and optics

The optics on the Blaze XLR are unremarkable, putting out a circular beam like most other entry-level single-piece headlights. The beam has a slight hot spot, but is sufficiently broad to illuminate obstacles and debris on a road or path.

Portland Design Works has been putting out classy, well-designed lights for several years now. The Lars Rover is their first foray into the ever-expanding arena of USB-rechargeable high-intensity headlights, following on the heels of their rechargeable Aether Demon taillight from 2013. It comes with a nice variety of high-quality mounting options, is certified to the FL1 Standard, has decent optics, and an excellent selection of flash patterns. Read on for more details.

Beam and Optics

The Lars Rover has a fairly standard circular lens. The beam pattern is fairly smooth, with good throw but enough flood to illuminate the sides of a road. There is no horizontal cutoff; the beam is almost completely symmetrical. This means it's necessary to tilt the light down somewhere to avoid blinding oncoming traffic.

I was quite impressed with the previous-generation Vis 180 when I reviewed it about a year ago, and the new 2014 model is very similar. The overall design remains the same: very sturdy construction using mostly metal and some durable plastic. A single bright, wide-angle red LED at the top, and a small amber side-visibility LED at the bottom. The output has been increased from 50 to 70 lumens, and the pulsing flash pattern has been modified slightly. If you already have a Vis 180 there's no pressing reason to upgrade, but if this is your first time looking at this light, read on for a detailed review.

Optics and visibility

The Vis 180's optics exceed what its name implies: the light is visible from well over a 180° range. The high-intensity primary red light is behind a custom reflector that spreads the light evenly across the horizontal plane, without wasting too much light by shining it skyward. The output of the lower amber LED is split to each side, and is also very bright. This combination makes the light visible from almost any angle behind or next to the bike.

The Light & Motion Urban series has been one of my favorites for a while, so I was excited to see the Urban 2.0 update this summer. The new Urban series carries the same design and features as the older series, but with redesigned internals. The lights are now fully waterproof, and all lights in the series have the peened reflector that debuted with the Urban 700. The Urban 350 in particular is exciting because it's the first L&M headlight that I feel is in the price and output range that appeals to the most riders. The Urban 200 wasn't bright enough, and the Urban 400 was a bit too pricey. At $70, the 350 hits a good balance between power and price.

Optics and visibility

The optics of the Urban lights are unparelled in this price and output range. Many lights in the 300ish lumen category have a relatively narrow beam that adequately lights up the road directly in front of you, but with no spill to see anything to the sides, but the 350 has a custom engineered reflector that creates a wide, smooth beam. Compared to the Serfas USL-305 with similar specs, the Urban 350 feels like it puts out way more than 50 additional lumens, because the light is put to better use.

Serfas already makes some of my favorite lights, but there was a large gap between their bright and bulky mountain biking lights and their small Thunderbolt be-seen lights. The 2015 (U)SL line changes all that, offering compact, low-weight lights with a good balance of visibility to see with and be seen by. The USL-305 weighs nearly half as much as Serfas' TSL-750, and puts out over 3x as much light as the Serfas Thunderbolt.

Optics and visibility

In my experience, optics have never been a selling point for Serfas lights. I've often criticized their TSL series lights for having far too narrow of a beam and a complete lack of side visibility. The beam profile of the USL-305 is a marked change from the TSL series, with a beam that isn't quite wide enough to illuminate an entire street, but more than adequate to see what's coming up in your lane or on the bike path. I often wished the light had a wider beam when I was rounding sharp corners, but otherwise it struck a good balance between flood and throw.

The Vis 360+ is one of the few bike lights I've seen that is designed specifically and exclusively for helmet use. As the name implies, it's meant to provide the rider with 360° of visibility. A small headlight goes on the front, connected via a springy cord to the rear light which is integrated into the battery pack. Both the front and rear lights have amber side visibility: the front light has filtered cutouts to allow some of the main beam to come out the side, and the rear light has separate yellow LEDs on each side.

The headlight provides a wide beam, putting out 250 lumens on high. It's not much compared to many high-powered headlights these days, but is quite sufficient to provide visibility for safety, which is what this light sets out to do. It's bright enough to find your way if necessary, but I wouldn't use it as my only light. The wide angle of the headlight combined with the amber side visibility ports makes the light very noticeable from the front and sides. The rear light isn't quite as bright (L&M doesn't specify its output either), but is definitely still very visible, and has great off-axis visibility. This is important, because riders' heads can be in many different positions, and a more focused beam would be hard to see if the rider's head was turned. The side visibility LEDs on the rear are small and so dim that they're practically pointless, but fortunately the side lighting from the headlight is bright enough to make up for it.

Cateye's Rapid series has been around for a while, and I was a big fan of the Rapid 5 in particular when I wrote my first taillight review back in 2012. Technology's evolved a bit since then, and Cateye's new Rapid X light is a dramatic departure from its predecessors. Rather than having several larger LEDs spread out across the light, the Rapid X has a bunch of minuscule LEDs lined up to appear as one larger bar of light. The light has an integrated USB-rechargeable battery, and is very light at just 23 g.

While the features sound good, in actual use the light is extremely frustrating. The circular rubber straps provided to attach it to the seatpost are very small, and must be stretched to the limit to attach the light. This makes it very difficult to quickly install/remove the light. You're also stuck having the light at whatever angle your seatpost is at, which for me meant the light shined mostly towards the ground, not towards traffic. Due to the rubber band attachment setup, there's no way to change the angle.

The TSL-750 is the first Serfas headlight I've tested since the TSL-S500 I reviewed last year. It has the same conveniently removable battery and handy mount, and a similar overall design. The 750 however is significantly bulkier than its predecessors, and weighs in at a hefty 195g, nearly 50% heavier than the TSL-S500.

Optics

My primary complaint with all of the Serfas TSL lights I've tested is the extremely focused beam and lack of side visibility. Unfortunately, the TSL-750 comes with a similarly narrow spot lens installed by default, creating an extremely bright yet very small circle of light that I didn't find useful for riding on roads or trails. However, Serfas is trying something new with the TSL-750: a wide "flood" lens comes in the box, and can be swapped out by the user. Swapping out the lens is not difficult, but it can't be done on the fly, and isn't epitome of user-friendly either. I'll go into a bit more detail on the lens swap process itself below, after describing the differences in using the two optics.

When MagicShine announced the Eagle 600, bike blogs and twitter feeds were abuzz about its OLED display that shows how much runtime the light has remaining. Although some other lights feature color-coded battery indicators, none before has literally told you how much time is remaining.

Battery life is important, and knowing how much time you have to get home before you're left in the dark is a welcome feature. But a light is much more than its battery display. The Eagle 600 gets several key features right that other lights lack, but also falls short in some critical areas. I'll get to a detailed analysis of that famed OLED charging display, but first let's discuss the other unique features of this light.

I'm a big fan of the Serfas TL-60 – it's really bright, sturdy, has decent battery life, and is easy to use. It had a few problems though: primarily a very narrowly focused beam, and no warning when the battery drops. The new TL-80 is a significant upgrade, addressing some of those problems.

Beam & optics

First, let's talk about beam pattern. Many lights – including the TL-60, and many popular lights like the Cygolite Hotshot and the Planet Bike Super Flash – have very intense but narrow beams. They form a bright spot that's visible from a long distance when viewed straight-on, but quickly loses intensity from any other angle.

Knog's well known for stylish lights, but I've often criticized them for putting form before function. With the new Arc 5.5, Knog has finally achieved a light that is as practical as it is slick. Featuring the familiar silicone housing, rugged aluminum, and smooth corners of Knog's other lights, the Arc impressed me by putting out more lumens for more hours than the preceeding Blinder Road.

The optics on the Blinder Arc 5.5 are particularly noteworthy. Many manufacturers all use the same generic TIR optics with some small differences in beam angle. The Blinder Arc features a custom-designed lens that spreads the light into a wider, smoother beam that illuminates the whole roadway instead of just a single spot. You can see the difference in the beamshot overlay above.