Minimalist Hydration for Fast-Paced Rides

The Osprey Seral 4 is designed for mountain bikers who want a streamlined, low-profile hydration solution without the bulk of a backpack. This technical lumbar pack includes a 1.5-liter Hydraulics™ Lumbar Reservoir, specifically shaped to keep the weight of your water low and centered on your hips for maximum stability. The hydration hose features a magnetic attachment that secures to the hipbelt, allowing you to drink on the move and snap the valve back into place effortlessly without taking your eyes off the trail.

Despite its compact 4-liter volume, the Seral 4 offers smart organization for your trail essentials. The zippered main compartment provides enough room for a spare tube, CO2 kit, multi-tool, and some nutrition, while the AirScape™ backpanel uses extra-thick foam ridges and mesh to ensure a breathable, comfortable fit against your lower back. The angled hipbelt and compression straps work together to pull the pack close to your body, eliminating bounce during technical descents and high-speed cornering.

Key Features:

• 1.5L Lumbar Reservoir Included: A specialized hydration bladder that contours to the small of your back to maintain a low center of gravity.
• Magnetic Hose Management: Keeps the bite valve secure and easily accessible on the waist belt for one-handed operation.
• AirScape™ Lumbar Pad: Ridged foam with a central air channel provides superior ventilation and a stable, cushioned fit.
• Stable Compression Straps: Pulls the pack’s weight toward the rider to prevent shifting and bouncing on rough terrain.
• Zippered Hipbelt Pockets: Two large pockets provide quick access to small items like keys, phone, or energy gels.
• Internal Organization: A main compartment with internal dividers ensures your tools and gear stay quiet and secure during the ride.
• Blinker Light Attachment: Includes a dedicated loop for a safety light and reflective graphics for increased visibility in low-light conditions.