Lupine Rotlicht rear light

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

* Flashing

* Pulse

* 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.

Verdict

Bright, solid rear light with a brake light function