What you need from a light depends a lot on the type of riding that you’ll be doing. If your commute takes you onto unlit roads or you’re up for some fast winter training times, you’ll need something that has a bright, far-reaching beam to light the road in front of you. Rechargeable batteries and battery indicator lights are useful when you’re out and about regularly.
If you’re keeping to street-lit areas with traffic, it’s all about being noticed by other road users – there are a lot of relatively inexpensive lights out there with long run times that will keep you visible from a range of angles without dazzling other road users. A light setup that attracts attention is what’s needed, but don’t just stop at lights, because this is where a reflective vest, sash, or backpack cover can come in very handy too.
Most lights use LEDs. Light emitting diodes emit light by being switched on and off quite quickly. If switched on and off for different lengths of time, it’s possible to increase or reduce light output. They’re very dependent upon the voltage for their efficiency.
Light mounts needs to be strong enough to hold the light over eye-rattling bumps, but also offer a quick-release style system that lets the light be easily and quickly removed. Mounts that require no tools to fit are a bonus, but this is by no means a necessary feature.
Switches and modes
The switch should be easy to use when riding, but hard to turn on accidentally to prevent the dreaded flat battery experience when you get your light out of your bag. They need to be well sealed, and offer at least one flashing mode and constant.
Some lights feature a beam pattern similar to that of a car or motorbike. This means the top of the beam pattern is essentially cut off, allowing a nice bright light to be used without it spilling upwards and dazzling other road users.