
On this Global Fat Bike Day (December 2), I find it fitting to share my thoughts on 45NRTH gear, a brand known for its exceptional cold weather and fat biking gear. In their latest lineup, they have unveiled two additions: the Ragnarök BOA Boot (unisex sizing) and the Grünnur base layer top, available in styles for both genders.
Ragnarök BOA Boot
https://www.45nrth.com/products/ragnarok-boot#/
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Price: $215
Sizes: 36-50 whole sizes only (no size 49)
Colors: Black or Grey
Closure: BOA Fit System with Li2 dial with hook and loop ankle
Temperature range: 25+F
Cleat compatibility: Two bolt
Availability: Online, Retail
How obtained: Company sample
RBR advertiser: No
Keep Feet Warm and Dry During the Shoulder Seasons
45NRTH recently dropped the latest edition of their Ragnarök BOA boot, and I’ve had the opportunity to test them on several rides in temperatures as low as 30 degrees F. I’m glad the 45NRTH team sent me the black version, as the grey reminds me of the storm trouper boots in Star Wars. Plus, the black is more sliming when you have large feet like I do – tested size 46.
Besides adding a grey color option, three notable updates to these boots include a new:
- Non-slip, real-rubber outsole with Hypergrip blocks and siping for better traction on slick surfaces
- EVA midsole to improve comfort underfoot while pedaling
- A floating “finger” design over the instep for an overall better fit
Compared to the previous tall version with a higher, neoprene ankle I reviewed last year, I did encounter some difficulty with the BOA system on the new lower ankle version. It was challenging to release the BOA system enough to slide my foot in and out of the boot easily. It would have been helpful to have a loop at the back of the ankle to assist with pulling the boot on. Additionally, longer BOA lacing would allow for a wider opening, accommodating different foot sizes more comfortably.

BOA Fit System with loop and hook ankle closure
After tightening the BOA laces and securing the loop and hook ankle strap, these boots are very comfortable for riding. However, due to the stiff soles, they aren’t great for walking or hiking. So, if you plan to hike-a-bike, ensure it isn’t a significant distance.
The sole of the Ragnarök boot features an anti-slip microglass rubber designed to increase friction on slippery surfaces such as ice, wet wood, linoleum, and metal stairs and floors. This rubber compound is electrostatically aligned with microscopic glass fibers, creating abrasive protruding shards that enhance traction.
I used 2-bolt SPD cleats with these boots, and installing and clipping them in or out was a breeze. Size 46 boot weighs approximately 654 grams according to my scale, so your legs may experience more fatigue than lighter cycling shoes with covers.

Two-bolt compatible cleats and anti-slip microglass rubber sole.
For my test rides, I paired the Ragnaröks with either 45NRTH lightweight knee socks or crew socks, which I reviewed last year and are still available on the 45NRTH website. The boots feature an ultra-thin sheet of microporous material behind their textile shells, which helps to keep feet dry and warm. The waterproof, breathable membranes prevent liquid from entering the boot while allowing vapor to escape, ensuring thermal and moisture regulation. As a result, my feet stayed warm and comfortable without becoming sweaty.
Cleaning these boots is a snap; using a damp cloth to wipe them down. This is particularly convenient when riding in muddy or wet conditions during the spring and fall.
Regarding visibility, the black version of the Ragnarök boot features a reflective strip down the back of the ankle and bright yellow piping. On the other hand, the grey version only has a yellow logo on the outside sole as its accent.
Overall, the 45NRTH Ragnarök BOA® boot is a good option for keeping your feet warm and dry during the shoulder seasons. Its improved traction, comfort, and waterproof features make it a reliable choice for riders looking to extend the riding season in cold and wetter weather conditions.
GRÜNNUR Base Layer
https://www.45nrth.com/products/mens-grunnur-baselayer#/



Price: $125
Sizes: XS-2XL (women’s); S-2XL (men’s)
Fit: True to size
Materials: 89% Merino Wool, 11% Nylon
Color: Cedar Sunrise
Performance and Comfort in a Merino Base Layer
45NRTH also introduced the Grünnur base layer in men’s and women’s versions a few months ago. Crafted with 89% Merino wool, this base layer checks all the boxes – soft, breathable, moisture-wicking, and warm. Available in men’s and women’s sizes, it offers a next-to-skin fit to wick away moisture and reduce bulk, ensuring optimal comfort.
Ditch the ordinary and opt for something different. The cedar sunrise (brown) color option is a refreshing departure from the typical black or white choices. With its longer sleeve length and rear hem, this base layer provides ample coverage, preventing chilly air from getting in.
I opted to line-dry this base layer after machine washing it. My only complaint is that it emerged from the washer wrinkled. You can iron the wrinkles out if desired. But since I’m not a fan of ironing, I’m glad the Grünnur top goes under my biking or hiking gear, where no one will see the wrinkles.
The Grünnur base layer, with its high-quality Merino wool fabric, delivers performance and comfort. Whether engaging in intense outdoor activities or simply seeking a cozy layer for everyday wear, this base layer has got you covered. And the unique cedar sunrise color adds a touch of style to your outdoor wardrobe.
Sheri Rosenbaum regularly contributes articles and reviews products for RBR. She’s an avid recreational roadie who lives in the Chicago area and a major advocate for women’s cycling, serving on the board of directors and volunteering with the Dare2tri Paratriathlon Club. Click to read Sheri’s full bio or visit her web site sunflowersandpedals.com.
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You chose neat products to reviews and do great reviews. Thanks