Fizik Terra Nanuq GTX winter boot review – Gore-Tex sealed and insulated MTB shoes

Fizik released the Terra Nanuq GTX winter boots late last year, ready to tackle the grotty winter climates that were inbound. Insulated and waterproofed with a Gore-Tex liner, they feature a high ankle cuff, Boa retention, and a chunky treaded Vibram sole.

Winter riding can play havoc on extremities. Hands get cold but are also easy to warm up again however feet are subjected to the worst of winter whether it's frigid puddle splashes or walking through snow. That means if you want to become a proper winter trail warrior a pair of well-insulated and waterproof MTB winter boots are going to be a worthwhile investment. I have been putting the Fizik Terra Nanuq GTX to the test to see if they can keep my toes cozy on the coldest days. 

Design and specification

The Fizik Terra Nanuq GTX's main form of defense against weather unpleasantries is the Gore-Tex Koala membrane. This thin layer works in the same way as Gore-Tex’s other waterproof jacket fabrics, featuring holes that are too small for water droplets to enter but large enough to allow water vapor molecules to escape thus giving Gore-Tex the breathability it's known for. A neoprene ankle cuff extends upwards to help stop puddle splashes from finding their way into the shoe and to further enhance the cozy levels, there is an insulated insole and fleecy lining inside.

Externally the Terra Nanuq GTX is covered in a ripstop fabric which is further protected by a generous amount of PU covering. Both the heel and toe cups feature a decent amount of protection from the gritty nature of winter and stumbling around on slippery rocks. 

Underneath Fizik has specced a chunky Vibram XS Trek EVO rubber tread with directional lugs to enhance grip in slippy winter conditions. The sole itself uses a Nylon shank and an EVA midsole with a stiffness index of three according to Fizik. The cleat is a standard two-bolt setup with a 32mm slot and some guidelines to help with lining your cleats up.

The Terra Nanuq GTX uses a single Boa L6 dial with a lace that crosses twice across the midfoot. The L6 dial allows clicks tighter and pops open to loosen. The ankle cuff has a short zipper to open the shoe up to help slip your foot in. Fizik has added a pull loop on the back too so you can tug them on.

Insulation and waterproofing are always going to add a bit more heft, but at 1028g they are still heavy when compared to Shimano GF800 GTX winter boots at 890g and Five Ten Trailcross Gore-Tex at 708g. In all fairness though, there are plenty of non-winterized enduro shoes that are around the same 500g per shoe weight.

Fizik offers the Terra Nanuq GTX in both the clipless version I have on test and a flat pedal shoe version that features a flat pedal optimized tread. Unlike many of Fizik’s shoes, the Terra Nanuq GTX only comes in a single Black / Grey colorway. Sizing spans between EU36 and EU48, with most sizes coming in half-size options as well. 

Performance

As Fizik states “warm feet are fast feet” and the Fizik Terra Nanuq GTX certainly performed well, keeping my toes cozy on the wettest and most unpleasant days. The comfortable fleece lining paired with my regular riding socks was all I needed on snowy rides to keep my digits warm. The Gore-Tex Koala membrane laughed off boggy hike-a-bike and puddle splashes keeping feet dry no matter how many times they were submerged. They aren’t infallible though, the cuff doesn’t always sit flush with the ankle and can create a gap if you drop your heels when riding. That means water can sneak in if your pant leg doesn’t extend well past the ankle cuff. Even with a little dampness working its way in, I still had warm feet.

Water might be kept out, but it isn’t trapped within either as the Terra Nanuq GTX delivers impressive breathability. On one test ride temperatures were significantly warmer than expected. Although I had properly toasty toes, the Terra Nanuq GTX managed moisture buildup very well.

The Vibram sole is very flexible which certainly aids walking, something which is a more common occurrence on winter rides due to wet and muddy trail conditions. The tread offers loads of grip and I had no problem scaling muddy, snowy, and slick grassy inclines. Despite the low stiffness rating, they don’t feel as soft on the pedals as you would expect. They aren’t going to feel as sharp as a summer trail or the best XC shoes when dropping watts although they still offer enough support when climbing or riding technical terrain.

Getting them on requires a little twisting of the foot to slide in but otherwise, it's a fuss-free process. The single Boa securely held my foot in place and I didn’t experience any discomfort from the neoprene ankle cuff’s zip. There is plenty of adjustment for cleat positioning and, despite being a little bigger and heavier than a standard shoe, I didn’t have a problem clipping in and out.

If they do get wet, winter boots are notorious for taking ages to dry again. The Terra Nanuq GTX impressed here, drying themselves out overnight next to a radiator. Not only does this mean you will have dry feet every ride, but it should hopefully reduce the build-up of unpleasant smells too.

Verdict

The make or break of a winter ride is often based on whether you can feel your fingers and toes during the ride. The Fizik Terra Nanuq GTX’s cozy lining, Gore-Tex Koala waterproofing, and high-quality construction kept my feet warm and comfortable on the winteriest rides. Winter shoes are never cheap and the $299.99 / £289.99 / €279 price tag is no small sum, if you can justify the cost Fizik’s Terra Nanuq GTX are a worthwhile investment for those who want to ensure winter warmth on a trail ride. 

Tech specs: Fizik Terra Nanuq GTX winter boots

• Price:  $299.99 / £289.99  / €279
• Weight: 1028g per pair (size 43 tested)
• Sizing: EU 36 to 48 
• Colors available: Black
• Rival products: Shimano GF800 GTX, Trailcross Gore-Tex, Leatt 7.0 HydraDri boot