With a claimed 640 lumens and four different power modes (one of which is flashing) to choose from, Knog’s Blinder ARC 640 front light certainly promises a lot.
You’ll need the adhesive foam strip that’s included stuck on your bar before fixing the Blinder in place though, as without it, even small vibrations can upset its position. The power button used to toggle between modes is small and fiddly to use in gloves. A small indicator light changes colour as the mode changes and you’ll see a helpful, separate red warning light when power is running low.
By alternating between the three non-flashing modes, we could get a few hours out of the Blinder before seeing the warning light. On the trail and at full power, the beam spread is impressive and its reach reasonable.
Though the Blinder ARC is okay as a standalone trail light, we think its better suited to being a backup light, using the helmet mount included.