Rear lights

Simson led-achterlicht voor bagagedrager

The Simson LED rear light is made to mount on a rear rack. According to the title it is waterproof and measures 80 mm.

What you get

LED rear light for racks
Waterproof according to the title
Size 80 mm

Why a good rear light?

A car coming up behind you sees you late. A rear light gives the driver more time to react, and it gets noticed better when it is bright, visible from the side and uses the right pattern. That is why many cyclists ride with a light on in daylight too.

Brightness is given in lumens. For city traffic and dark roads, 15 to 50 lumens is usually enough. To stand out in daylight, choose 50 to 100 lumens or more, in a flashing or pulsing mode. More lumens means shorter battery life, so there is always a trade-off between brightness and runtime.

The mode matters a lot. A steady light is always easy to see and shows the distance to your bike better. A flashing light draws attention faster, but makes it harder to judge distance. A pulsing mode sits in between. Also look at side visibility: a light that also shines left and right makes you visible at junctions.

Check the rules in your country. In many countries the light must be red and may flash or burn steadily. Some countries require an approved light, for instance with a road-use mark.

How the modes compare

A rear light usually offers several modes. They differ in visibility and runtime.

Mode	Visibility	Judging distance	Battery	Best for
Steady	Good	Easiest	Shorter at high output	Dark roads and groups
Flashing	Very high	Harder	Longer than steady	Daylight and city traffic
Pulsing	High	Fairly good	Between steady and flashing	All-round, day and dusk
Eco mode	Moderate	Good	Longest, often tens of hours	Long rides and tours

Runtime and brightness vary by model.

Choose it if

Your bike has a rear rack and you want a fixed light on it
You also ride in the rain and want a light that can take it
You ride on roads with cars, in daylight too, and want to be noticed early.
You ride at dusk, in rain or through winter.

Choose something else if

Your bike has no rack and you want a light for the seatpost
You only ride on closed or car-free routes and want a simple light: a basic model will do.
You want to know what is coming up behind you: a radar light adds that.

How to use a rear light

Charge it
Charge the light fully before you go. The indicator lamp often shows the charge level.
Mount it on the seatpost
Clip the light to the seatpost or saddle bag. It should point straight back and not be hidden by your jacket or bag.
Pick a mode
Choose steady in the dark and on busy roads, pulsing or flashing by day. Use an eco mode for long rides.
Check before you ride
Step behind your bike and check that the light works and sits straight.

Good to know

Check the hole spacing on your rack for the fixing
Find out how the light is powered: battery or dynamo
Check the runtime in the mode you actually use. The stated time often applies to the most economical mode.
Keep the USB port or charging cable cover closed against water. Moisture in the port shortens the life of the light.
A clamp that works loose over time lets the light tilt down. Tighten it.
Keep the light on your bike for daytime rides too. Visibility works best when it becomes a habit.

What you get

Why a good rear light?

How the modes compare

Choose it if

Choose something else if

How to use a rear light

Charge it

Mount it on the seatpost

Pick a mode

Check before you ride

Good to know

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