Greg Weber's Blog

Bicycle Lighting

January 24, 2018

In cycling there are multiple ways to promote safey. Lighting your ride is an important if you ride at night.

I came up with these three principals of bicycle lighting.

  • light your own way
  • be considerate (don’t blind others)
  • be visibile to others

Lighting your own way

Mostly you just need a strong light on the front of your bicycle. A helmet mounted light can help to see where you turn your head.

Being Considerate

  • Light should be diffuse: spread out rather than coming from a single point
  • Use red light rather than white

Would like to get a light with great optics that don’t disturb others like the Busch & Muller Ixon Core However, this is really hard to buy in the USA

Note that being considerate can also help you meet all legal standards. Specifically,

  • In some US states it is illegal to have flashing lights
  • In Germany there are very strict regulations about bicycle lights (no flash, angled down, intensity)

Be visible to others

  • both front and back lights
  • high contrast
  • moving light is better
  • In daytime, lights should be blinking or standout somehow

Many cyclists buy fluorescent clothes. Its important to note that motorcycle research shows that in a daytime environment, contrast is key, and fluorescent is not necessarily the best contrast. Additionally, this research shows that lights that stand out in some way are best.

The best clothing is probably highly reflective (and most fluorescent clothing has reflectors).

Reflectors provide value given that they cost so little and require no power. However, reflectors are a very limited tool to improve visibility. Their effectiveness improves with movement (ankle reflectors).

A study on cyclist visibility states:

“Drivers recognised more cyclists wearing the reflective vest plus reflectors (90%) than the reflective vest alone (50%), fluorescent vest (15%) or black clothing (2%). Older drivers recognised the cyclists less often than younger drivers (51% vs 27%). The findings suggest that reflective ankle and knee markings are particularly valuable at night, while fluorescent clothing is not.”

Pulsing light would seem to obviously help in visibility, but I haven’t seen studies for that yet. Variable rate pulsing may be even better.

It is also claimed that 2 lights with a distance between them can help oncoming judge changing distance.

There are some Less obvious lighting options to think about

  • lights attached to backpack or clothes
  • lights attached to helmet
  • point a light onto yourself rather than only at others (diffuse, recognize a person)

A helmet mount helps create two points of light when paired with bicycle mounts. It can also put light out to the side or the direction you are looking.


  • Lithium Ion batteries, not AA (for more power)
  • Reflecting ankle bands (any brand) $6-20

    • Simple, cheap, no power, moving light reflector
  • A front light that is adjustable in intensity, direction (can be pointed downward), and is diffuse instead of blinding
  • Rear facing lighting

    • has 2 sources (helps judge distance)
    • 1 source has some blinking capabilities
  • Side-facing light (can look for rear lights that have this)
  • Helmet light

My purchases

In researching lighting, I cam across this site and went with their recommendations.

Greg Weber

Written by Greg Weber who lives and works in Silicon Valley building useful things.

Blog comments powered by Disqus.