Rudy Project Cutline review – photochromic sunglasses for MTB trails

I'd never been a fan of photochromic lensed sunglasses for mountain biking. While they're quick to darken, every lens I'd tried was too slow to clear once I'd entered a dimly-lit area such as the woods. The Rudy Project Cutline glasses with its ImpactX 2Laser Red lens changed all that though and are definitely one of the best mountain bike sunglasses I've ever tested.

Design and specifications

Rudy Project's Cutline sunglasses come in a wide range of frame and lens options. I've been testing the Matte Black frames with the ImpactX 2Black lens ImpactX along with a 2Laser Red lens – available separately.

The semi-flexible lenses are said to be unbreakable "for life", though the warranty is for two years. ImpactX lenses are made using "patented polyurethane optical polymers" which Rudy Project says results in a lens that's lighter than polycarbonate and plastic alternatives. The lenses are also treated with a number of different anti-reflective and hydrophobic layers and coatings, they're also vented with four slots in the upper part of each lens.

The frames are a mixture of stiff (arms and hinges) and flexible (everywhere else) rubberized plastic. The nose piece can be adjusted to suit, and the total weight for the glasses is an average 36g. If you want to lighten the load on your face or change your look, you can convert the full-frames to half-frame or barely any frame, as the top and two bottom sections can be removed individually. You can also customize your glasses by buying a frame kit of a different color and swapping out the interchangeable parts.

There's plenty of flex in the glasses and the arms point slightly inwards to softly grip the slides of your head, while the tips of the arms turn slightly outward.

Performance

I've been testing the Cutline glasses for many months in a wide range of riding and light conditions and have been seriously impressed. The glasses feel secure yet light and comfortable, and have worked well with every helmet I've tried them with. Lens quality is top notch and the glasses are big enough so as not to impair your vision in any way.

The supplied 2Black lens works well in open riding conditions. However, like every photochromic model I've tried, it's too slow to return to clear when entering darker sections of trail – which forces you to drop your pace for the four minutes or so that the lens takes to react to the dimmer light.

Switching to the additional 2Laser Red lens (sold separately but also available with different frames) made a huge difference though. Red lenses work well in shady woodland conditions, so the time it takes for the lens to lose its tint has never been an issue even when plunging from full sun to forest darkness.

I've been really impressed with how tough the ImpactX lens is too. The Cutlines have been regularly splattered with winter filth, stuffed into packs and pockets while already dirty and without their soft case, but remain scratch and mark-free after many months of riding.

Almost as impressive is how resistant they are to fogging. I've had zero issues with them at lower temperatures, but have had occasional mild fogging when working hard on slow climbs during hot days. The lens clears as soon as more air moves past them though and I've yet to ride in a pair of glasses that never fog up at some point.

Verdict

Rudy Project's Cutline glasses with an ImpactX 2Laser Red photochromic lens are an excellent option for almost all light conditions. In fact, the only time I've taken them off to see more clearly has been in wooded trails when riding after dark – as there is still a minuscule tint in the lens even at its clearest.

Scratch resistance on these glasses is second to none. The Cutlines have been properly mistreated but there's not a mark on the lens.

One very minor point is that you can't actually buy the Matte Black Cutline with the 2Laser Red lens I've tested here unless you shell out for an additional lens. However, it is available with the red/back Carbonium frame option and both models come with the same $269.99 / £219.99 / €254.90 price tag.

Tech specs: Rudy Project Cutline sunglasses

• Price: $269.99 / £219.99 / €254.90
• Additional lens price: £99.99 
• Lens type: ImpactX (photochromic)
• Weight: 36g
• Spares available: Lenses and frame kits
• Rival products: 100% S3