Rear Dynamo light not turning off


Keep Calm and OMG.......CAKES!!
I have a set of Busch & Miller dynamo lights on a new Genesis Tour de Fer touring bike.
Only been out on the bike once so far with the lights on and the rear light didn’t turn off when I switched the front off which then drained the power
I’m new to dynamo lights so is this the norm or do I need to return the bike to the shop?
Or is there a fix I can make myself


Senior Member
Run your finger along the bottom of lamp is there a little red bit you can press? Turns light off


Senior Member
^^^ wot Bruce said^^^

Both front and rear lights have a built in capacitor that gets charged as you cycle along.
When you stop both lights stay on by using the capacitor, they usually hold about 4 minutes of charge.
It's a safety feature, some rear lights have an off switch but not all.


Legendary Member
^^^ wot Bruce and Tenkaykev said.

It's called a standlight. It can be a problem when wheeling my bike at railways stations. I keep a small neoprene purse to slip over the light.

I also leave the lights on daylight sensor all the time. It saves a lot of faff.


Keep Calm and OMG.......CAKES!!
Run your finger along the bottom of lamp is there a little red bit you can press? Turns light off
No switch so it’s linked to the front light


Perhaps This One.....
My Topline has a small button underneath to allow you to turn it off when in standlight. I've always assumed its for when you leave your bike parked up, a lit rear advertises an expensive front wheel perhaps?
A lot of Busch and Muller lights have a red button and a tiny slider switch, which is easy to miss.

The red button dumps the capacitor, so kills the light at rest.

If you push the bike, the light will illuminate again.

The slider switch isolates the rear light entirely - it will always be off.

I believe the feature is aimed at taking the bike on trains.

Showing a red light on a railway station platform is strictly forbidden.

You might want the light off if you need to push the bike along the length of the platform to reach the loading point of the train.
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