Koo Supernova sunglasses

The Koo Supernova sunglasses are good looking and function well as cycling specific eyewear. They are incredibly light with a wide field of vision, but lack the customisability of many rivals – and they're relatively expensive, too.

Koo is the eyewear brand of well-known helmet makers Kask, so it's no surprise to find these are light and, thanks to the rimless lens, give you a great view of the road ahead.

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I tested the white frames with a Red Mirror Zeiss lens. This is my favoured combo for sunglasses (they match nicely with a white helmet), but Supernovas available in six colour schemes, with various lens options to match the anticipated light level for your riding.

The Red Mirror lens here has a 'VLT' (Variable Light Transmission) rating of 23% and works well in medium to bright sunlight – in truth, they're most appropriate for summer cycling. For winter riding, I would probably select a lens which allows more light through, especially in 'flat' light.

Clarity is good, if not as good as the Oakley Prizm Road lens, for instance – that has a similar red tint and offers better colour definition (the tinted Prizm lens showed up recently in the Oakley Sutro Lites).

I never had the Supernovas fog up at all when climbing, even though the relatively large lens blocks a bit of airflow at the forehead. For my preferences, they were fine.

I found the Koo Supernovas comfortable. The lens is pretty flexible so adapts well to different face shapes and sizes, and the rubber nose-piece creates a good separation from your face. However, when paired with my Medium Specialized Prevail helmet, the arms would slightly clash with the retention system.

This certainly shouldn't happen with a Kask helmet, though unfortunately I don't have one to try so I can't comment.

Otherwise, at only 22g these things are barely noticeable once on. Personally though, I think I'd take a few extra grams in exchange for a little more customisation – removable parts, basically.

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The fixed lens here means the entire pair of sunglasses would need replacing if you scratched them badly, and of course you can't swap to different tints – you need a whole extra pair. Some glasses also let you change the length of the arms, which can be particularly useful when pairing with different helmets.

Value

At £169.00, these come in towards the top of the market, and comparable frameless glasses are available for less. The SunGod Arias ZF are £130 and got 8/10, for instance, while the Oakley Sutro Lites are currently £149.

Overall

The Koo Supernovas are clearly a good pair of cycling sunglasses, combining an unobstructed view of the road with a super lightweight design. For me though, a few more customisation options and a lower price tag would make them more compelling against such strong competition.

Verdict

Good looking, effective and extremely light, but they lack customisation – and the price is high