The Lupine Rotlicht is a bright rear light with a couple of clever functions to help keep you safe on the road.
The light is made with a CNCed aluminium housing and it attaches to your bike via a simple rubber strap that'll reach around anything up to 140mm in diameter (actually, a bit more if you stretch it). Chances are that you'll attach it to your seatpost, in which case it'll reach easily and the angled plate at the back will make the light sit more or less vertically.
It weighs in at a highly reasonable 62g and it's waterproof.
You can choose from four different modes:
* Steady and pulse
You can also adjust the intensity of the light in each of those modes, choosing from up to five settings (depending on the mode) from 10 lumens up to 160 lumens.
Put the Rotlicht (German for 'red light') into constant mode at its highest setting and it is powerful (don't take too much notice of our light comparison engine here). It won't dazzle other road users but the Cree XP-E2 LED will certainly get you seen, even in the urban jungle with the background noise of a million other lights.
What of those clever functions I mentioned?
First, the Rotlicht comes with a light sensor that you can run in either high or low settings, or turn off entirely. This sensor measures the level of ambient light and adjusts the output accordingly. When car headlights shine on it, for example, the light becomes brighter. It's subtle but this light sensing function certainly does its job.
The other smart feature is that the Rotlicht can act as a brake light. There's an accelerometer in there that senses when you're braking and makes the light glow brighter. It doesn't react to bumps, just to significant deceleration. You can choose from three different levels of sensitivity.
Again, this function does work as promised, and if it doesn't appeal to you it can be switched off. Do you need a brake light on a bike? It's certainly not essential. Is it helpful? Perhaps, to give those behind you a little extra information about what you're doing.
The Rotlicht is powered by a micro USB rechargeable lithium polymer battery that can be replaced at the end of its life. You get around 90mins of power in the brightest constant setting rising to about 30hrs in the lowest constant setting, and that still provides enough light to get you seen.
If you go for the flashing mode, you can get 3hrs of life right up to 60hrs, depending on the brightness setting you use.
Ah yeah, there's one other unusual little feature. When you switch the light off, it blinks to tell you how much charge you have remaining. As battery level indicators go, it's okay but it relies on you remembering that four blinks, for example, mean the battery is about half full.
Other drawbacks? Setting the brightness level, the light sensor and the brake light all require a bit of memory too, or reference to the instruction sheet. Still, once done you'll probably stick with the same settings most of the time, so that's not a biggy.
All in all, this is a really strong proposition. It's certainly one of the more expensive rear lights out there but if the light sensor and brake light functions appeal, you're getting a lot for your money.
Bright, solid rear light with a brake light function
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road.cc test report
Make and model: Lupine Rotlicht rear light
Size tested: n/a
Tell us what the light is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
Lupine say, "The Lupine Rotlicht is probably the brightest and most intelligent bike rear light on the market.
"With incredible 160 Lumens of red light output this is probably the most powerful tail light with integrated battery. In addition to the incredible brightness, the Rotlicht has some incredible features like a brake light and brightness sensor. With this light you won't be overlooked anymore on the streets.
"When you pull on the brakes, the built in acceleration sensor turns the light brighter to gain more attention on the streets.
"Automatic light adjustment depending on the ambient light. If for example a car comes closer, the light turns brighter."
Tell us some more about the technical aspects of the light?
Lupine list this technical data:
LED: Cree XP-E2
Power: 0.1 - 2W
830mAh / 3Wh
Protection Class: IP68/ IK09
Plug: Micro-B USB
It feels solid without being weighty thanks to a CNCed aluminium casing.
Setting the brightness level, the light sensor and the brake light all require the instructions sheet first time around. You might remember how to do it a couple of months down the line, or you might not. The number of pushes of the button you need for each setting are printed on the light itself, it's just a matter of remembering how to access each mode.
It's a simple rubber strap. It could hardly be easier and it has been perfectly secure throughout testing.
There are four modes and five intensities so it's easy to select one that'll last as long as you need it to, right up to 60hrs.
That aluminium casing can handle a bashing. The light itself has been covered in mud and grit and all sorts over the past few weeks yet a quick wipe has it looking as good as new.
It's a bit heavier than a simple plastic blinky, but not much more considering the extra tech on offer here.
£80 would be a lot to pay if this was a simple rear light, but it isn't; this has light sensor and brake light functions too.
Tell us how the light performed overall when used for its designed purpose
It performs really well. It is bright and very easy to fit and then remove between rides. The extra functions work as promised too.
Tell us what you particularly liked about the light
Brightness, ease of fitting, rechargeability.
Tell us what you particularly disliked about the light
I didn't find the setting procedure particularly intuitive.
Did you enjoy using the light? Yes
Would you consider buying the light? Yes
Would you recommend the light to a friend? Definitely
Anything further to say about the light in conclusion?
Yes, it costs quite a bit more than a standard rear light, but if you're going to make use of the extra functions on offer here that price seems justified.
About the tester
Age: 43 Height: 190cm Weight: 75kg
I usually ride: My best bike is:
I've been riding for: Over 20 years I ride: Most days I would class myself as: Expert
I regularly do the following types of riding: commuting, club rides, sportives, general fitness riding,
Mat has in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been road.cc technical editor for over a decade, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a winner of the Cycling Media Award for Specialist Online Writer. Now pushing 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.