Due to the output requirements, the Lupine SL X e-bike light is only compatible with Bosch, Brose and Shimano but not Yamaha bikes
Lupine lights are some of the best mountain bike lights we’ve ever tested, and the SL X is no different. It has a lightweight machined body, with a remote switch and super-minimalist (31.8 or 35mm) bar clamp, allowing you to get it really close to the stem. Unfortunately, the back of the lamp did contact the faceplate on our Race Face stem, so the single clamp could do with being slightly longer. Lupine does offer a double clamp option for an extra €12, but we don’t know if it offers any more clearance.
The Lupine SL X is sold with a dedicated connector, but it looks like you can splice in another plug if you change brands down the line.
Setting up the system is straightforward – you simply remove the cover on the motor (you may have to remove a crank to do this first) plug in the light and configure the Bosch software. We routed the cable inside the frame, but you don’t have to – there is space for the cable to exit the plastic cover and then you could just zip-tie it externally to the frame.
The lamp unit has a central LED housed inside a massive Fresnel reflector, but it’s surrounded by nine automotive LEDs. These are for riding in daylight and are active all the time, but at any point you can flick on the main light via the bar-mounted remote. You then have high and low beam options. And if all that sounds like something you’d find in a car, the beam pattern is similar too. In the low setting it has a long, oblong shape, but fire up the high beam and it fills in everything above that, just like a car headlight. The light is amazingly bright and really white, which is perfect for picking out detail. And all that light at the sides means you can easily see around corners; it really feels like you have more than 1,800 lumens on tap.
The Lupine SL X is easily the best made e-bike light out there. It’s also one of the brightest and we’d say it has the best light quality too, but the elephant in the room is the price – it’s a lot of money for just a lamp.