Klim Nac Pak with Shape-Shift 3L HydraPak Review

When choosing a backpack for a multi-day ADV ride, or in my case a three-month exploration of the Backcountry Discovery Routes, one might be tempted to opt for a large capacity backpack. However, riding gnarly trails requires frequent standing on the pegs, which adds up when you ride day after day for three months. Trying to alleviate fatigue, I searched for a medium-sized backpack with a hydration bladder and sufficient quick-access cargo space for essential lightweight items. I opted for the recently redesigned Klim Nac Pak with Shape-Shift 3L HydraPak, which turned out to be an excellent choice.

In contrast to Klim’s largest capacity backpack, the Krew Pak, the medium-sized Nac Pak does not feature a hip belt, which was initially a concern when I contemplated my choice. However, my doubts were quickly put to rest after the first day of riding. The previous generation of the Nac Pak had proven to be popular, but Klim is well known for continuous product development and implementing improvements based on customer feedback. Klim incorporated input from rally racers and RTW riders in the new design to enhance the ergonomics, developing a close-fitting chest/shoulder harness that keeps the backpack from flopping about when bouncing over rough trails.

The great revelation of the Nac Pak was that the ergonomic design works so well that I completely forgot not only that the harness had no hip belt, but also that I was überhaupt (at all) wearing a backpack. Klim achieved this ergonomic marvel by integrating the new race-inspired shoulder/chest straps with the sternum and side straps. The padded shoulder and side straps feature easy-to-operate adjustment buckles that stay firmly in position. Once adjusted and cinched tight, the harness is securely locked in place by the foolproof round buckle of the sternum straps, enabling a snug and comfortable fit like I’ve never experienced before with any other backpacks.

The Nac Pak features four compression straps that help fend off distractions by preventing loose items from moving around in the backpack when the going gets rough. The Nac Pak’s ergonomics are further enhanced by the molded and vented back panel that’s thick enough to function as a back protector in case you’re not wearing one.

Klim’s relentless pursuit of perfection shows up in ingenious details, like the goggle chamois suspended from an elastic strap inside the sturdy goggle case at the top of the pack. Another example of advanced ergonomics are the zipper drawstrings with large molded loop ends that make operating the YKK heavy-duty zippers while wearing gloves so much easier.

The Shape Shift 3L HydraPak is a significant upgrade from my previous hydration bladders. The folding top slide closure is an innovative improvement on the conventional round screw lid design as it enables easy filling and facilitates turning the bladder inside out for cleaning. Other practical features are the internal organizer panel with various pockets and key chain clip as well as the carrying handle, which I found very convenient for keeping the backpack off the ground by hanging it from the handlebar when parked.

Another valuable item included in the Nac Pak is the removable water-resistant Tool Pak which comprises two elasticated webbing panels and a mesh pocket to carry and organize tools. A surprisingly convenient feature are the two zippered pockets on the chest/sternum straps ideal for storing a personal emergency locator beacon or tracker, phone, earplugs, balm, sunscreen, etc.

With the redesigned Nac Pak with Shape Shift 3L HydraPak, Klim has scaled new heights in ergonomic backpack design for ADV riders. With its durable heavy-duty nylon construction, adequate cargo capacity, large hydration bladder, well-organized tool pouch, and über-ergonomic harness, the Klim Nac Pak served me exceptionally well during my BDR marathon, and therefore I recommend it without reservation.

The Bottom Line

For trail and rally-style days where you need water, tools, and recovery gear on your back rather than the bike, the Nac Pak earns its keep. It's not the cheapest hydration pack on the shelf, but the harness comfort and the external tool storage are the two things that actually matter once you're three hours into a ride, and both are done right. If your riding is mostly street and commuting, the smaller, slimmer Arsenal 15 is the better fit — save the Nac Pak for the days you know you'll need the shovel.