Bonfus Fastus 23L


Weight: 360 g

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A revolutionary backpack for fastpacking adventures. If you’re looking for the best, this is the answer. The Bonfus Fastus 23L is the latest masterpiece from the Bonfus design table.

The Fastus 23L embodies the fast & light philosophy. It’s a trail running backpack made from ultralight premium materials. The vest-style straps feature built-in stretch and a breathable mesh structure. The upper part of the straps is strategically padded with 4mm foam.

The volume of the Fastus has been chosen well, fitting ultralight overnight gear without adding unnecessary bulk. We believe this size is optimal for fastpacking backpacks.

Loaded with clever details from various attachment points for trekking poles to the flexible bottom pocket accessible from both sides.

Bonfus Fastus 23L

A revolution in lightweight outdoor gear. Engineered for fastpackers and runners, this backpack is your perfect partner for ultralight adventures. Its sleek design strikes the ideal balance, offering enough volume for fast-and-light overnight trips without the excess bulk or bounce during a run.

Crafted from advanced tough materials, the Fastus 23L is ready for the challenges of fastpacking. The vest-style straps with built-in stretch, featuring breathable mesh fabric and strategically placed 4mm foam over the shoulders, provide tailored comfort and flexibility. With five pockets on the vest straps, including a zippered one, a clever bottom pocket for quick double sided access and multiple lashing options for your trekking poles, it’s designed for on-the-go efficiency. Its size and elegant design make it also perfect for everyday use and urban adventures, too!

Engineered for ultralight fastpacking endeavours. The vest-style straps are crafted for comfortable and stable load transfer to shoulders and torso, wider than standard padded shoulder straps to spread pressure seamlessly. With built-in stretch and elastic edge binding, they adapt to your body, ensuring greater mobility and comfort. Roomy pockets facilitate quick on-the-go storage access. Developed with a minimalist, ultralight approach, this backpack provides what you need without unnecessary bulk and weight. Hand-built with the expertise of our skilled sewers, it combines simplicity with craftsmanship.

  • Ultralight Design: the Fastus boasts an ultralight design, ensuring you can move swiftly without unnecessary weight.
  • Optimal Size for Fastpacking: perfectly sized for fastpacking adventures, this backpack provides enough volume for overnight trips without becoming too bulky during high-intensity runs.
  • Vest Style Straps: featuring vest-style straps with five pockets, including one zippered compartment. This design ensures convenient storage and quick access for soft bottles, water bottles, and other items like electronics and snacks during your journey.
  • Soft Flask Security: an elastic ribbon above the soft flask pocket secures the tip of the soft flask, preventing excessive movement and ensuring stability.
  • Stretch Pockets with Elastic Cord: stretch pockets with elastic cords and cord-locks offer versatile and secure storage options, allowing you to expand or tighten the pocket openings as needed.
  • Efficient Roll Top Closure: the backpack features an aluminum G-hook for quickly securing and compressing the roll top strap.
  • Breathable Mesh Straps: crafted with breathable mesh fabric with a slight stretch, the vest-style straps reduce sweat and move seamlessly with the body, enhanced by elastic edge binding for added comfort. The vest straps are wider than standard padded shoulder straps found in other packs; this allows the load to be spread to a wider area around the shoulders and torso, so the straps can better “hug” your body for enhanced load stability for fastpacking.
  • Strategic Foam Padding: 4mm EVA foam, placed exclusively above the shoulders on the vest-style strap, provides targeted comfort, allowing breathability and flexibility for the rest of the vest straps while further reducing weight.
  • Adjustable Sternum Straps: the backpack features two sets of sternum straps with elastic webbing, adapting to your torso’s natural expansion and contraction during breathing and movement.
  • Quick Trekking Pole Storage: enjoy quick and on-the-go storage of trekking poles on the vest-style straps or alternatively on the side of the pack for added convenience.
  • Bottom Access Pocket: the bottom of the backpack features a dual-access stretch mesh pocket, ensuring quick and easy access to essential items from both sides.
  • Spacious Front Mesh Pocket: generously sized front mesh pocket, providing additional storage for items you want to keep within easy reach.
  • Side Compression Cord: 6-point side compression cord not only stabilizes the load but also secures items, providing versatility in packing.
  • Ice Axe Loop: for those icy adventures, the built-in ice axe loop ensures you’re prepared for any terrain.
  • Webbing Belt: a 25mm detachable webbing belt is included to additionally stabilize load and reduce pack movement.
  • Taped seams: only when choosing Ultra200 as pack material. Seam tape is applied to increase water resistance and increase seam strength. A pack liner is suggested to ensure pack content remains dry.
  • Fabric Options: available in Ultra200x and UltraGrid fabrics, providing durability and performance tailored to your needs. See more in the “Materials” section below.

Material: Ultra 200X (130gsm | 3.85oz/sqy) – Probably the most advanced pack fabric on the market. It features woven 200D UHMWPE fibers. At a slight weight increase compared to DCF2.92, the Ultra 200 fabric has 3x higher tear strength, 3x higher UHMWPE fibers content, 7x the abrasion resistance. The backing of the fabric is a .75mil recycled polyester film and X-grid, that makes the fabric extremely waterproof.

Color: Black

Volume: 23 L

Weight: 360 g, Webbing belt (included) adds 35 g

One size, 42cm back length.

Unrolled height: 60 cm
Top circumference: 75 cm


Weight 360 g

1 review for Bonfus Fastus 23L

  1. Nina Hongenaert (verified owner)

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