Zerk 55 UL Backpack

Go ahead, take some extra luxuries...Grueling trails don't stand a chance against our all new ZERK 55!

The ZERK 55L, the original cornerstone of our ZERK UL Series, has been tested & developed thru 10's of thousands of thru-hiking miles and co-designed with The Real Hiking Viking (AKA Jabba). When the goal is to hike faster, longer and with more efficiency, consider this award winning pack on your next ultralight adventure. 

For this newly updated version, we've added new Zerk accessory compatibility and included modular compressions straps and field serviceable bungees; not only increasing your versatility on the trail, but also allowing you to strip the weight when thru-hike minimalism is key. 

Additional upgrades for 2026:

• Materials upgraded to Robic® Nylon X-Grid Extreema (UHMWPE) Ripstop with UTS coating for both the 210d fabric (bottom panel, backpanel and reinforcement areas) and 100d fabric (main body)
• Ultra durable Spundura stretch mesh pockets with UHMWPE grid in key wear areas (Side bottle pockets and front panel sleeve pocket)
• Additional upper side panel stretch mesh pockets for quick access, on-the-go items (avocados anyone?)
• A new front panel zippered security pocket for improved organization of trail valuables
• Compatibility with our new Zerk 3L Loki Lumbar pack which acts as a chest rig on the ZERK 40 shoulder straps or carry it stand alone with the existing ZERK 40 waistbelt; enabling you to pack the Loki Lumbar as an organizer pouch and then use it as a stand alone lumbar pack for side trips from base camp without carrying an extra waistbelt!
• Compatibility with our new Zerk 7L Toplid accessory, increasing your carrying capacity by an additional 7L
• Changed interior pattern volume to better accommodate some makes of 700 in³ sized bear canisters

FEATURES

• Roll top closure with opposing SR buckles for self closing roll top or for side panel attachment with removable straps
• Extra wide shoulder straps with dual adjustable sternum straps
• 4 Large mesh front pockets on shoulder straps (2 per side) accommodate 500ml bottles, bear spray, cell phones, gps units, etc
• Airflow EVA foam padded shoulder straps
• Modular side compression straps (removable) for securing load throughout entire pack or discarding entirely
• Customizable and removable front panel bungee system
• Removable, padded waistbelt with two side zippered pockets
• Large main compartment holds up to 53 liters of gear with extra 5L storage in roll top area
• Expansive front stretch mesh pocket made with ultra durable Spundura (w/ UHMWPE grid) for hauling bulky gear
• Reflective bungee and select webbing hits for increased visibility
• Removable interior frame sheet (EVA / Atilon)
• Dual side water bottle pockets made with ultra durable Spundura (w/ UHMWPE grid) stretch mesh and angled openings for easy access
• Adjustable over-the- top V-shaped compression strap with SR buckle closure
• Hydration bladder sleeve with hose port (Bladder Not Included)
• Bright yellow lining promotes visibility

MATERIALS

• 210d Robic® Nylon X-Grid Extreema (UHMWPE) R/S UTS*
• 100d Robic® Nylon X-Grid Extreema (UHMWPE) R/S UTS*
• Spundura Stretch Mesh (w/ UHMWPE grid)*
• 150d High Density Poly Liner*
• YKK® Zipper
• EVA Foam
*There are no intentionally added PFAS in this item

CALIFORNIA WARNING: Cancer and Reproductive Harm | www.P65Warnings.ca.gov

DIMENSIONS

• 11” x 24” x 9" (W x H x D)

VOLUME

• 3234 in³ / 53 L
• 3540 in³ / 58 L (Extended Roll Top)

CAPACITY

• Waistbelt Size Range: 28"-48"
• MD Torso Range: 16"-20"
• LG Torso Range: 18"-22"
• Weight Load: Suggested up to 40 lbs, but can accommodate 25% more (ie., 50 lbs) for your next sufferfest

WEIGHT

• 3 lbs 8 oz / 1.59 kg