Knog Blinder ARC 640 review

The Knog Blinder ARC 640 is a sleek front light, but can its function match its form?

Cycling Weekly Verdict

The Knog Blinder ARC 640 is a good front light which is bright enough to be used in some pretty gloomy conditions, and is also very easy to use. However the mount isn't secure enough to keep it pointing in the right decision, which is a major flaw.

Reasons to buy
  • +

    Sleek design

  • +

    Integrated mount

  • +

    Easy to use

  • +

    Fairly bright

Reasons to avoid
  • -

    Mount could be more secure

  • -

    Integrated charger is fiddly

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Compared to many other front lights that cost less than £100, the Knog Blinder ARC 640 has a very sleek design. The mount is permanently attached to the bottom of the light body, meaning there’s no chance of accidentally losing one or the other. However I found that the mount wasn’t very secure, and on bumpy roads it would often rotate backwards, meaning it was pointing skywards rather than at the road - not on potholed tarmac where I needed to exactly what the roads had in store for me.

>>> Best front lights for under £100

As for the light itself, 640 lumens is a little on the low side, meaning that I wasn’t too confident heading out into unlit lanes with just the Knog attached to my bars. However, if you’re just commuting under street lights, or want a nice simple light to attach to your bars when heading out for early morning rides, then it’s a really good option.

knog blinder arc 640 front light

The Knog Blinder ARC 640 has a very sleek design

For your money the Knog Blinder ARC 640 you get three constant modes, and one flashing mode, which are easily switched between using the button on the top of the light body. There are also status lights, which change colour to indicate what mode you’re in and battery life.

>>> Buyer's guide to rear lights

A final feature is the fact that the USB plug is integrated into the back of the design, but although this cuts down the number of wires on your desk, it makes it a little fiddly to attach.

For more details head over to Todays Cyclist (opens in new tab).

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Henry Robertshaw began his time at Cycling Weekly working with the tech team, writing reviews, buying guides and appearing in videos advising on how to dress for the seasons. He later moved over to the news team, where his work focused on the professional peloton as well as legislation and provision for cycling. He's since moved his career in a new direction, with a role at the Department for Environment, Food and Rural Affairs.