Dazzling other road users is a bad thing for both your safety and society’s goodwill toward cyclists on the road. Please don‘t use a torch for a front lamp! You need a shaped beam, like a car’s dipped headlamp, for riding among traffic. Besides, a shaped beam shows the road surface better than any torch no matter how bright. Even illumination is better than an extreme hotspot.
For a rear lamp, you ideally want a few things:
- continuous illumination (flashing makes it hard to judge distance – something essential for passing car drivers)
- large surface area (or failing that, long lines of light), again to help judge distance and therefore closing rate
- deep red colour, not orange or washed-out pink
- collimated light in centre of beam for distant visibility
- spill over a wide range of angles at much-reduced brightness, for visibility in close traffic and during passing manoeuvres
- not so bright even in the collimated beam that it dazzles drivers and cyclists behind you.
Few lamps meet these criteria but, as usual, the better dynamo lamps come closest.
It is an easy mistake to think that greater brightness means greater safety.
