When it comes to choosing the right bike light, visibility (when you're out cycling on the road) is essential, but durability, size, ease of fitting and removing, and battery replacement are also important. Here are a few other things to consider:
USB rechargeable batteries get rid of the need to charge or replace removable batteries.
Bike lights with multiple LEDs are usually brightest, but a single LED can still be very bright if the light has a good reflector.
Check the light is clearly visible when side-on or at an angle.
Try the different flash rates – if the flash is too slow you’ll travel further between each flash, giving motorists an inaccurate judgement of your location. If it’s too fast, it’ll create a strobe effect, again distorting motorists' judgement of your exact location.
Ensure that light mounting brackets fit your bike.
If batteries are required they should be easily obtainable ones, such as AAs or AAAs.
Helmet-mounted lights aren’t ideal when sharing a path/road with other users. They are more suitable for mountain bike riding in the dark.
As a general rule:
Check your lights regularly. If they’re looking dim, it’s time to replace the batteries or recharge them.
Carry a backup set of lights with you.
Wear light-coloured or reflective clothing (or a reflective strip or vest).
Mount your lights at handlebar height, so you're more visible.
Test the lights in-store before buying them.
High-powered lights are most visible when their flash mode is in use. When they are in constant beam mode, their light can meld with the surrounding street and traffic lights. They are great if you’re riding on an unlit path, however, their bright light can blind other other riders and drivers. If you want to use a high-powered light for riding on lit roads, ensure they are pointed down at the ground and a few metres in front of the front wheel. Another option is to mount a compact front light to switch to when riding on a lit road or track.