The Deuter Flyt 18 mountain bike pack; (photo/Eric Phillips)

Deuter Flyt Bike Backpack Review: A Protective, High-Volume Pack for Mountain Biking

Deuter recently launched an ergonomic, protective mountain biking pack for men and women, and after hundreds of miles in the saddle, the pack has proved to be among our favorites for off-road adventures.

As a long-time player in the pack category, Deuter has a robust smörgåsbord of mountain biking packs. For long trail days or overnighters, pedalers can opt for the 2-pound Compact EXP 14L with many compartments and an expandable volume to organize gear.

There’s a lightweight lineup for racing or downhilling at the ski area: the Race 8L, Race Air 10L, and larger-volume Race EXP Air 14L (plus an additional 3L expansion). Or bikepackers can use the 30L Trans Alpine 30.

But in spring 2021, Deuter launched a mountain bike pack series with a lightweight back protector for additional safety.

Over the past two mountain bike seasons in Colorado, I tested out the Deuter Flyt 18 SL ($200), a mountain bike backpack in the Flyt series with an 18L volume and the women’s-specific (SL, or Slim Line) fit.

In short: The Deuter Flyt packs ($190-200) include ample well-designed pockets for storage, excellent back ventilation for heart-pumping climbs or hot days, but best of all, a unique, integrated, removable back protector. The pack is available in four volumes and in men’s- or women’s-specific fits.

The Deuter Flyt 18 SL mountain biking pack on a ride; (photo/Eric Phillips)

Deuter Flyt 18 SL Bike Backpack Review

The Flyt collection boasts the same great features as its Deuter pack siblings, from smart pockets to an integrated rain cover. But, it also has a certified lightweight back protector for additional safety.

On adventures with the Flyt, I rode technical singletrack in the mountains out my front door in Gunnison Valley, including rides around Crested Butte and the high-alpine desert at Hartman Rocks Recreation Area.

My day rides typically ranged from 10 to 45 miles and 1,300 to 6,300 feet of gain/loss. I also wore this pack on the remote alpine-to-desert Palisade Plunge, a 32-mile technical and cross-country route in Palisade.

riding mtb with deuter flyt
(Photo/Eric Phillips)

Deuter Flyt 18 SL Bike Backpack Specs

  • Pack weight: 1,130 g (2.49 lbs.)
  • Size range: 38-48 cm back length, 158-178 cm (5’2″ to 5’8″) height
  • Dimensions: 46 cm x 26 cm x 18 cm
  • Volume options: 12L and 18L options for women’s, 14L and 20L options for men’s
  • Volume tested: 18L
  • Material: PFC-free tight-weave, high-tenacity 210-denier and 100-denier nylon fabric blend
  • Pockets: 5 external pockets, 5 internal pockets
  • Safety: Emergency whistle, third-party-certified removable safety back panel
  • Features: Integrated rain cover, exterior helmet clips and straps, hydration bladder compatible, hip belt, back ventilation

deuter flyt

Where This Pack Shines: Organization & Compartments

I love organizing odds and ends in my biking backpack, especially because traveling in the mountains usually entails a healthy amount of gear. Unless I’m going on a shorter ride that’s 10 miles or less, in which case, I wear a hip pack.

Nonetheless, I’ve learned the hard way that even with tubeless tires, I need a minimum repair kit: tube, hand pump, levers, bike tool. I also bring a Garmin inReach, snacks, water, rain jacket, first-aid kit, Leatherman, eye drops, extra glasses with clear lenses, and my phone.

On longer, remote rides, I’ve also carried a water filter, headlamp, bike light, and extra warmer gloves.

Deuter Flyt

The Flyt has two spacious storage compartments, and tons of pockets, including two mesh side pockets, a zippered exterior side pocket (which is accessible with the pack on), two zippered hip belt pockets, an interior zippered goggle-sized pocket, two interior mesh pockets, and two interior deep elastic pockets.

There’s an interior elastic band for securing a portable bike pump, and a tiny elastic band on one shoulder strap for sliding the arm of your sunglasses.

testing deuter flyt
(Photo/Eric Phillips)

Hydration Storage

The largest interior compartment has a hydration sleeve for a 3L bladder. The hose easily threads through an opening at the top of the pack. Then there’s a Velcro strap on both shoulder straps for securing the hose.

On the Palisade Plunge, I also used both of the side mesh pockets to carry hard-sided water bottles, due to the lack of water along the trail and near-triple-digit climate. The bottles never jostled out. On other rides, I’ve also used those side mesh pockets for keeping a soft flask handy when I want to separate my electrolyte mix from the rest of my water.

(Photo/Eric Phillips)

Men’s- vs. Women’s-Specific Fit

In step with other Deuter backpacks, the Flyt series is offered in a men’s (also known as “regular”) and women’s fit, denoted as “SL,” which stands for Slim Line.

SL pack models have a shorter silhouette: the shoulder straps are narrower, have flexible edges, and are curved in an S-shape to compliment the bust area. The hip belt has a cone design that softly folds over the hips and tapers into the waist.

The SL packs are built by women for women, but can generally be used by any riders with narrower, slimmer body profiles. As someone with a short torso, narrow waist, medium-sized chest, and round shoulders, the SL pack design fits so comfortably I don’t even notice it’s there.

If you have long legs and a short back, check out the SL models. Or, if you’re a guy that typically wears size small or medium apparel, the SL packs could be a good option for you.

Testing out the women’s Flyt 18 SL backpack; (photo/Eric Phillips)
Women’s (SL):
  • Flyt 12 SL: 12L, 38-48cm back length, 158-178cm body height
  • Flyt 18 SL: 18L, 38-48cm back length, 158-178cm body height
  • Flyt 14: 14L, 44-54cm back length, 170-195cm body height
  • Flyt 20: 20L, 44-54cm back length, 170-195cm body height

Hip Belt and Adjustable Straps

Deuter Flyt backpack

Overall the hip belt on this pack is really comfortable and seamless, and I’ve never experienced bruises, blisters, or hot spots after long days.

Two streamlined buckled straps on each side of the pack compress the pack or hold a full-face helmet on the front of the pack. There are also plastic clips on the front of the pack to slide in helmet straps, but they aren’t easy to use, so I don’t usually depend on them. There are also load adjusters on each shoulder strap to help snug everything up, if the descent gets rowdy.

Ventilated Design

Two deep, vertical (cushioned) pads along the back prevent the pack from sitting flush against the rider, allowing airflow down the center. The shoulder and hip belt strap materials are quick-drying and breathable. The back protector is built to ventilate, as well.

riding mtb with deuter flyt bac´kpack
The Deuter Flyt 18 SL mountain biking pack on a ride; (photo/Eric Phillips)

Removable Back Protector

It goes without saying, I didn’t want to test the back protector on flying descents — but I crashed. Hard. And the back protector held up!

The back protector slides easily out and into a streamlined, zippered sleeve that’s closest to the rider’s back. When you remove the back panel, there’s a neon fabric that’s visible through a mesh window to indicate the missing reinforcement. I remove the protection armor when I clean my pack, but otherwise, leave it in the sleeve.

At only 150 g (0.33 pounds), the ultra-lightweight shield is made from high-end EPP (expanded polypropylene), which is a closed-cell bead foam that absorbs energy upon impact. It’s resistant against multiple blows, water-resistant, and has a high strength-to-weight ratio. The material is also recyclable.

Specifically, this LB-L back protector is manufactured by SAS-TEC, which specializes in body protection systems. It’s designed with a honeycomb pattern that allows ventilation despite the fact that the material is supposed to provide thermal insulation.

Given the back protector is shielded from the elements and is not next-to-skin, the material lifespan is longer than a bike helmet, which should be replaced every 5 years, according to the nonprofit Consumer Reports.

Deuter Flyt Bike Backpack Review

As a sweaty rider, I haven’t felt like the protector retains my body heat. The material is flexible and ergonomic enough that I don’t feel rigidity in the pack. Also, I appreciate that there’s a boundary between the items in my loaded pack and my back.

The Flyt’s Geprüfte Sicherheit (GS) safety certification indicates that the design has been evaluated by TÜV SÜD, a third-party accredited organization for GS testing, and meets the German Product Safety Act.

The back protector is suitable for cross-country and mountain biking, as well as activities like rollerblading. Following a crash or major impact, Deuter will replace a back protector free of charge, even if there is no visible deformity, within 2 years from purchase. Beyond that 2-year warranty, Deuter can still offer a crash replacement.

Despite that I’ve gone over the handlebars on some technical descents and took a major whipper on a downhill, the back protector remains without dents and cracks.

More Safety Features

An emergency whistle integrates into the sternum strap. Inside the pack, there’s an SOS infographic, which includes emergency call numbers for Europe and the U.S., as well as hand signals for air rescue. These infographics and safety features are par for the course for all Deuter packs, and most technical daypacks in general.

Deuter Flyt Bike Backpack: Conclusion

riding mtb with deuter flyt backpack -
(Photo/Eric Phillips)

The Deuter Flyt is a solid contender for mountain bikers, whether you’re heading out on an after-work lap or taking the entire day to explore, especially if you need to carry extra supplies or nutrition. With a variety of volume and fit options, the pack is suitable for everyone, including shorter or slimmer builds.

The only issues I’ve noticed with the pack are that the helmet clips on the front are a bit finicky — and my helmet is the last thing I want to drop! Also, sometimes the pack load sits unevenly, and I need to reorient the hip straps. But otherwise, I don’t need to make many adjustments as I ride.

In addition to the integrated rain cover, it’d be great if the exterior material was water-resistant. I was once caught in a hail storm 5 miles from home, and the pack got soaked.

Also, this pack could supplement a bikepacking trip, but if I had the option to, I’d size up to the 20L Flyt (available in men’s but not SL).

Overall, this mountain bike pack really impressed me with its design. When I need to carry a full day’s worth of hydration, food, and gear, this pack checks all the boxes. The Flyt pack is comfortable, fits well, and adds extra elements of protection while keeping my gear super organized.

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The Deuter Flyt 18L on a testing ride; (photo/Eric Phillips)
Morgan Tilton

Staff Writer Morgan Tilton is an adventure journalist specializing in winter sports coverage, travel narratives, and outdoor industry news. A recipient of nearly a dozen North American Travel Journalists Association awards, when she’s not recovering from jungle expeditions or doing field research in far-out villages she’s usually trail running, mountain biking, river surfing, or splitboarding in Colorado’s San Juan and Elk Mountains, where she grew up and lives today.