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

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.
-
+
Sleek design
-
+
Integrated mount
-
+
Easy to use
-
+
Fairly bright
-
-
Mount could be more secure
-
-
Integrated charger is fiddly
You can trust Cycling Weekly.
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.
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.
Thank you for reading 20 articles this month* Join now for unlimited access
Enjoy your first month for just £1 / $1 / €1
*Read 5 free articles per month without a subscription
Join now for unlimited access
Try first month for just £1 / $1 / €1
Get The Leadout Newsletter
The latest race content, interviews, features, reviews and expert buying guides, direct to your inbox!
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.
-
REI expands its cycling business, becomes exclusive US retailer for Van Rysel gravel bikes
The expansion further includes partnerships with Rocky Mountain, Swift Industries, Stio and Peppermint Cycling
By Anne-Marije Rook Published
-
'I had something left at the end' - Primož Roglič wins first race of 2025, beating Juan Ayuso on stage 4 of Volta a Catalunya
Slovenian wins summit finish at Montserrat Mil·lenari and takes race lead
By Adam Becket Published
-
How to watch E3 Saxo Classic 2025: Everything you need to live stream the mini Tour of Flanders
All the information on broadcasters and live streams for E3 Saxo Classic on 28 March, as Mathieu van der Poel and Wout van Aert take on 'mini Tour of Flanders'.
By Tom Davidson Published