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Help Looking for automatic lights


Aug 2, 2016
Hello everyone!

First post here so my apologies if I´m posting in the wrong section :)

I am planning a 3 month trip in Japan with my girlfriend. We have been touring before, but never in a place full of tunnels like Japan, so our light setup is not up to the task and needs upgrading.

Please assume we will not have a place to charge our stuff for days so having the lights on during the whole day is not an option.

I am looking for rear lights (since front lights are more accessible while riding, I could use non-automatic lights) that turn on automatically when going inside a tunnel, so I can keep the batteries up for weeks.
The lights could either be dymano-run or any other system really. For the rear one is not so important that is a dynamo-run light since it doesn´t use as much battery.

Preference towards a light that I can setup in the back of the bike, because my rainjacket goes over my helmet.

I would love to hear from other users that have tried automatic lights, and I am open for other suggestions, keeping in mind that my girlfriend will probably go mental if she has to ride behind me while I have a flashing light on the whole day.

Rear lights that could be activated remotely, if that even exists, would also be okay. I think you get the point :)

;tldr: I´m lazy and don´t want to get off my bike before and after every tunnel. Need automatic lights.


Maximum Pace
Mar 20, 2013
Look for a light that has a large button on the side. As you ride into the tunnel, turn the light on. Once you exit the tunnel, turn it off. If you can grab a water bottle while riding, you can most certainly reach back and turn on a light without having to stop.

Half-Fast Mike

Lanterne Rouge-et-vert
May 22, 2007
Have never heard of or seen automatic lights, although technically they are feasible. I use bar end lights on all my drop-bar bikes. No need to stop or dismount; rolling illumination. #NoDismountEnvy

hat and beard

Maximum Pace
Apr 3, 2012
Some models of Busch and Muller dynamo lights have an automatic on / off function.
I would go for dynamo hub driven lights front and rear and just leave them on all the time. Modern dynamo hubs from Shimano and Shutter Precision are affordable and require only a few watts of leg power. 3 of my 4 bikes have dynamo lighting and I don't notice any extra resistance compared with my "fast" road bike.
Also I don't know of any rear dynamo lights that blink, so that's not a problem.

For both affordability and performance I suggest a Shutter Precision hub, Budch and Muller Lumotec IQ front light and any Busch and Muller dynamo powered rear light.


Maximum Pace
Apr 8, 2008
Yes Cateye make the ones that come on automatically. Some friends use these.

I use the volt series which you switch on yourself but come with extra batteries as an option. I always leave the back on flashing

Most top end cateyes are charged by a USB cable so easy to charge at some point on the road I would imagine.

Also seems a shame to choose routes with tunnels. Almost all tunnels still have the original "toge" pass going over the top. And if you've got 3 months, I would avoid major roads altogether. Maybe rethink your route a little?

I find Japanese drivers to be courteous especially in rural areas but busy roads and especially tunnels will always be dangerous.




Aug 2, 2016
Thank you @hat and bearde and @andywood for some useful advice there.
I was actually thinking on buying a SP dynamo (which model do you use?) and I will definitely have a look at the B&M front light you recommend.

I would prefer a blinking rear light because I believe that makes me more visible, so I might get an automatic one that runs on batteries and use the dynamo to run the front lights and charge a small battery pack I can use to recharge devices while I sleep.

Regarding the tunnels and the routing... I´m 100% up for avoiding tunnels and taking alternative routes but I have been told it´s not realistic to think I won´t be going through a lot of tunnels in this 3 months. It´s reassuring to hear that most of them still have the original pass!

I have been checking some roads and I will try to avoid roads with lots of tunnels or with a long one without alternative. My girlfriend really hates them and they stress her out, specially the ones without shoulder, so I´m trying to do as much as I can to avoid the stress by picking the roads and installing a decent set of lights that make her more comfortable.


Sincerely A Dick
Nov 14, 2011
A super cheap option.... solar powered rear lights?
I have never used one, but you can find them on amazon shipped for under $5.

hat and beard

Maximum Pace
Apr 3, 2012
I was actually thinking on buying a SP dynamo (which model do you use?)

All SP hubs are essentially the same. The only difference between the different models is that some are intended for disk brakes and some for rim brakes. There are also different models for wheels smaller than 26 inch. Just get the hub that matches your braking system and wheel size.
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