The Sigma Buster 700 costs the same for both the handlebar or helmet mount options, and weighing under 150g it works great in either location, although we’ve been running it primarily as a helmet light for this test. The Buster 700 has four light modes – high power 700 lumens, a standard mode 350 lumens, a 170 lumens eco mode and basic flashing option.

• Best MTB helmet lights

Charging is via a micro USB, housed under a silicone flap on the back of the light and there’s a cable included in the box. Run-time is a claimed two hours, but we found it’s more like 90 minutes, although it does recharge relatively quickly. The switch also doubles as a battery life/charge indicator: clear is between full and 71%, green 71-31% and red is under 30%.

Sigma Buster 700 beam

With only 700 lumens, the Buster 700 isn’t the brightest light we’ve tested, but the focused beam pattern lets you easily pick out obstacles on the trail and look round corners. It also has one of the best mountain bike light helmet mounts we’ve seen. The flexible base moulds to the contours of your lid, which is great if you have odd-shaped vents or any ridges in the micro-shell. It’s secured via a Velcro strap and has a little pivot, so you can also angle it up or down. It even has a GoPro compatible interface built in, so if you have an integrated camera mount on top of your helmet, this will bolt straight on.

We have a few minor criticisms – the switch requires two ultra-fast clicks to turn it on (it’s called Switch On protection) and takes a bit of getting used to, and the secondary power settings are just too weak for off-road use.

The Buster 700’s low weight meant we couldn’t feel it when riding, so we didn’t need to ride with the helmet too tight, and it’s also low-profile, so it never came close to snagging on branches. On paper 700 lumens doesn’t seem like a lot, but the light quality and focused beam makes it a perfect partner to any 1,500 lumen bar light.