To be safe while cycling it’s important to not only ride defensively but to also make sure other people see you. Compact and bright daytime visible lights are one essential way to ensure that. Today we’ll be looking at Topeak’s answer to daytime visibility which is the new Headlux 100 USB. At only $27.95 the Headlux 100 USB is one of the smallest front lights in Topeak’s Headlux lineup. The two 0.5W white LEDs can put out up to 100 lumen of output and are powered by an integrated 500mh Lithium Ion battery. Topeak has also incorporated the USB dongle directly on the rear of the Headlux 100 USB which means the light has a cable free design and can be directly plugged into USB Type-A ports for charging.  With its compact size and simple rubber strap mount design, the Headlux 100 USB can also be mounted on aero bars, round bars, helmets or under center mounts.

The Topeak Headlux 100 USB is a compact be-seen style headlight with a clever integrated USB dongle and bi-directional mounting design.

Retail Price$27.95
Rating 8.8/10
Measured Weight (in g) 36
Likes+ Built-in USB dongle
+ Simple bi-directional mounting straps
+ Compact and lightweight form factor 
Dislikes– High-frequency flash is a bit annoying
– Have to cycle through all modes to turn on and off
– Lacks a battery status checker
Where to Buy (US)Topeak


The Topeak Headlux 100 USB comes packed in Topeak’s characteristic white/yellow cardboard box. A plastic window in the front of the box allows you to interact with the headlight and see the headlamp up close. Inside the box you’ll find:

  • Headlux 100 USB headlight
  • Long rubber strap for handlebars
  • Short side rubber strap for out-front mounts
  • Rubber pad for out front mount option
  • Instruction manual

The multiple mounts is a nice feature that isn’t typically included with front lights and provides a lot of flexibility.


With the small form factor of the Topeak Headlux 100 USB it’s not surprising that Topeak has chosen simple rubber strap mounts. It’s the same design as the Topeak Headlux 450 USB with two integrated plastic posts on the left and right side of the housing. Topeak refers to it as bi-directional tool free design as the two included straps allow the Headlux 100 USB to be mounted perpendicular to handlebars or parallel to out-front mounts. The handlebar mounting is a bit confusing as you have to wrap the strap around the mounts twice. It’s not nearly as convenient as Garmin style mounts found on lights such as the Magicshine Allty 400 but makes it compatible with a variety of handlebar shapes. Topeak also includes an extra rubber pad that fits over the curved rubber pad that helps angle the light downward when mounted under out-front mounts.

Topeak Headlux 100 USB Review - Side
The Headlux 100 USB has a compact form factor and simple bi-direction mounting that makes it easy to mount on helmets, handlebars or stems.


As a “be-seen” headlight it’s not surprising that the Topeak Headlux 100 USB is a small light. It’s not much larger than a USB thumbdrive which means it can be easily mounted in a variety of locations. Thanks to the plastic body and lens the Headlux 100 only weighs 52 grams which means you’ll hardly notice it if you mount the light on your helmet. The light design is very similar to the Topeak Headlux 450 USB with a two LED setup, rounded rectangle profile and symmetric body. The main difference between the Headlux 100 USB and the 450 USB is the plastic construction, smaller size and lower output. Branding is limited to Topeak and Headlux 450 printed on the sides of the housing.

Topeak Headlux 100 USB Review - Charging
With an integrated USB dongle, you don’t have to worry about finding the right cable to charge the Headlux 100 USB.

The Topeak Headlux 100 USB has a simple one button interface with a large rubber button on top of the light. Unlike most bike lights which can be turned on or off with a long press, Topeak has used only a single press interface. That means you have to cycle through the three modes to turn the light on or off. It’s not as convenient as other lights but with only three modes it’s easy to get used to. Note there is also no mode memory as you always have to cycle to the off mode manually. Instead of a backlight power button, Topeak has opted for a separate LED below the button that indicates charging status and low battery status. We would have preferred a multi-level battery status indicator like those found on the Magicshine Allty lights as you can’t check battery status before riding.

One of the most unique features of the Headlux 100 USB is the cable-free design. Topeak has accomplished this by integrating a USB Type-A dongle directly into the rear of the body. It’s protected from the elements by a soft rubber cover. This means you don’t need to worry about carrying a charging cable with you and can instead directly plug the Headlux 100 USB into a USB outlet to charge. The design is similar to the Light and Motion Vya Pro and works well for compact bike lights. Compared to the Vya Pro or Magicshine Allty lights, the Headlux 100 USB is quite a bit simpler as it lacks motion sensors, ambient light sensors or battery status checkers.


Topeak has integrated three simple output modes with the Headlux 100 USB. A high constant, low constant and finally a flash mode. Both of the LEDs operate together in all the output modes and are capable of a maximum 100 lumen. Topeak doesn’t provide the lumen output per mode and instead only specifies the runtimes. High mode is good for 1.5 hr, while low mode is 3.3 hr  and flash mode offers an impressive 40 hr runtime. The flash mode is the most useful mode of the Headlux 100 USB as it is ideal for daytime visibility. Although the flashing pattern is annoying with a very high frequency on/off pattern, it can help keep you visible when riding.

Topeak Headlux 100 USB Review - Dual LED Lens
The Headlux 100 USB features a dual LED design with two 0.5W white LEDs. capable of 100 lumens.

The high and low constant modes can be used for city commuting or urban riding but we don’t recommend them as your primary light for night time riding. Instead the Headlux 100 USB can be combined with more powerful light setups for extra visibility at night though. The beam pattern of the LEDs are simple circular beams without any beam cutoffs and complicated reflectors. We do wish Topeak had added some side windows though as the side visibility of the light is limited to the slight convex curvature of the front lens.


Overall, we found the Topeak Headlux 100 USB to be a versatile and compact bike headlight. The clever bi-direction rubber strap mounting design makes it easy to mount the Topeak Headlux 100 USB on helmets, round/aero handlebars, aero extension bars or even under out front mounts. At only 100 lumens the Headlux 100 USB is best used as only a “be-seen” or for urban use. We found the flash mode worked well for daytime visibility and with a 40 hour runtime didn’t require frequent charging. The integrated USB dongle also makes charging easy as you don’t need to keep track of cables and can plug the Headlux 100 USB directly into a USB outlet to charge. Although the Topeak Headlux 100 USB doesn’t have as much power or features as other lights in the price range it’s a well built headlight with clever mounting and charging features.

Disclaimer: The product for this review was provided by Topeak. The views expressed on this website are solely those of the authors and are here to help people make an informed choice before a purchase. The authors or the blog itself does not get any monetary compensation from the product manufacturer or third-party websites/vendor links that are posted here.

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