The Sigma Karma Pro Headlight

There are plenty of headlights to choose from and they run the gamut in design and functionality. We think the Sigma Karma Pro at at 5600 Baht hits a beautiful balance between the two. The lightweight but powerful Sigma Karma Pro head unit is about the diameter of a D battery, 38mm long and weighs 70grams. IT has only one small button: click twice quickly to turn on, once more to increase to standard power and then again to the brightest setting. Hold for two seconds to turn off. There no flash setting, since in Germany, Sigma's home country, only emergency vehicles are allowed to have flashing lights.

For handlebar mounting, there is an overlapping click bracket not much bigger than the light itself, that fits on standard or oversized handlebars. The light sits on an adjustable swivel that allows you to turn it left and right independent of the mounting bracket. The rechargeable lithium ion battery is about the size of a cell phone, 20mm thick, and weights 140grams. Its slim mounting bracket straps onto the bike frame. The last bit of hardware – the cable: Sigma gives you a 76cm power cord to supplement the 40cm cord should the situation require. The ends snap together and seal to protect the connection. There's also a special zip tie to hold the cable in place. Assembly is quick and easy, and when not in use the entire system is compact enough to slip into a pack or even a jacket pocket without being awkward of heavy.

Sigma also includes a helmet bracket in the South-East Asian region with the same easy mounting channel, so you can switch the headlight between the handlebar and helmet. Some assembly is required for the helmet bracket, but if you can't handle a small Phillips head screwdriver you shouldn't be out on the bike anyway.

We where very pleased with the high power setting (12w, 35 Lux, 200 lumens) on the Sigma Karma Pro, and thought it depletes the battery quicker (about 3.5 hours of battery life), we found its concentrated powerful focus with wide diffused halo worked nicely for illuminating peripheral objects. We where confident navigating during a nightly downhill at Khao Yai National park. The standard setting (8w, 25 Lux, 150 lumens) gives you an additional 2 hours battery life and was adequate for navigating as the only light source. The lowest setting, (4w, 15 Lux, 100 lumens) extends your battery life to 11 hours, but we only felt comfortable on this setting when there was supplemental street lighting available. It's better than pitch darkness though. The focus of the beam didn't change in the lower settings.