Fast V4

■Specs

■Size Guide

■ Introduction

SAYAMA works' backpack development began in earnest in 2018, sparked by a request from an athlete competing in the Trans Japan Alps Race (TJAR)—renowned as Japan's most grueling mountain race. To survive extreme conditions so punishing they induce hallucinations, the design rigorously pursued a symmetrical universal layout, seamless functionality allowing access to essentials without removing the pack, and ultra-lightweight engineering that shaved off every single gram. After a relentless process of creating more than ten prototypes in just six months, the completed model successfully guided the athlete to the finish line.

Inheriting the overwhelming DNA of this top-tier racing gear, the "Fast" was born from a new challenge: bridging the gap between mountain climbing and everyday life. To overcome the hurdles of mass production for general sale, the brand spent two years collaborating closely with factory planners, repeatedly creating samples and re-engineering the design. By establishing a streamlined production flow meticulously calculated for craftsmanship ease, effortless maintenance, and cost reduction, they successfully brought their ideal vision to life in 2021.

While encapsulating the exceptional functionality forged in TJAR, the "Fast" has transformed into a simple, beautiful design that blends seamlessly into daily routines. Built with an even greater emphasis on durability than its racing predecessor, it achieves a ruggedness meant to be cherished for years to come. Furthermore, starting with the 2026 "Fast V4" model, the shoulder harness features a "LITTLEAID®" tag—a testament to their patent-pending innovative idea. The functional beauty born on the extreme ridges continues to evolve, elevating itself into the ultimate tool for everyday adventures.

■ Features

• Main Compartment: Inherits the silhouette designed for TJAR 2018. The bottom-to-top expanding capacity design delivers high stability and exceptional carrying comfort.

• Roll-Top: Features a drawcord system for instant access to your gear. Made from 70D ripstop nylon in black to seamlessly conceal dirt.

• Front Direct-Access Zipper: Centered with a No. 5 YKK water-resistant zipper for direct access to the main compartment. Equipped with highly visible dual silver sliders.

• Grab Loop: Positioned on the front side to prevent any interference with your neck.

• Front Side Pockets: Large-capacity left and right pockets that can be smoothly cinched with one hand. Features heavy mesh for easy visibility of contents, with the side gusset expanded to 4 cm (+2 cm compared to previous versions) to significantly boost storage capacity.

• Bottom: Equipped with a multi-functional system to securely fasten sleeping mats or trekking poles. Unified with stain-resistant X-Pac VX21 Black material.

• Shoulder Harness: Streamlined design for an outstanding fit, equipped with 8 mm thick urethane padding and load lift straps. Features the patent-pending "LITTLEAID®" system to prevent slippage, while minimizing bottle interference with your arms (Recommended height: 165 cm – 179 cm).

• Chest Strap: Features an elastic mechanism that does not restrict rib cage movement, paired with a whistle buckle for enhanced safety.

• Back Panel (Torso Length): Utilizes double russell mesh to quickly absorb and diffuse sweat. Prioritizing everyday practicality, the torso length has been increased from the conventional 43 cm to 48 cm.

• Hip Belt: Made of 25 mm high-density nylon that can be detached at any time for daily use. Engineered with modular expandability to dock the new "Rising" pack, scheduled for release in 2026.

• Reservoir Pocket: A hydration-compatible pocket (with a tube port) that can also double as a compact laptop sleeve for daily use. It houses a three-folded mat inside; based on race-proven feedback, the internal divider was eliminated to maximize weight savings. Features easy-to-use dual sliders.

■ Attention

Please note that there may be slight variations in the placement of parts and loops, as different craftsmen handle the sewing for each section. Thank you for your understanding.