Oxsitis Gravity 10L Review: 170 g, 9 Pockets, 2 Soft Flasks

Every trail runner knows the Oxsitis name, even if few have actually worn the brand. With the Gravity 10L, the French hydration specialist delivers a 10-liter vest at 170 g built for total versatility: compact enough for a long run, organized enough for several hours of self-sufficiency. Here is why this €119.95 vest belongs on your shortlist before your next big outing.

Oxsitis Gravity 10L: the do-it-all vest from France's hydration specialist

Oxsitis is one of those French brands that built its reputation on a single playing field: hydration for road running and trail. No shoes, no watches, just belts, packs and vests designed to carry water without disrupting your stride. The Gravity 10L is now the centerpiece of the range, the all-rounder that sits between the minimalist skyrace format and the big self-sufficiency pack.

With 10 liters of capacity and 170 g on the scale in size M, it competes with the Kiprun Bag 900 10L and the Compressport Ultrun Evo 10 V2, while claiming richer organization. At RunMorph, we see the 10-liter segment as the most hotly contested in the market, because on its own it covers the vast majority of what amateur trail runners need, from a 3-hour outing to a 50 km race with partial self-sufficiency.

RunMorph tip: don't pick your first vest on color or brand, pick it on adjustment. A poorly tightened 10 L vest bounces as much as a regular backpack. The Gravity bets everything on its side velcro closure, so test it fully loaded before settling on your size. If you are torn between two capacities, also read our review of the Raidlight Ultralight 12L to compare a slightly larger format.

© Oxsitis, official photo used for editorial purposes

Objective technical data

Who is the Gravity 10L for?

The runner who wants one vest for everything

This is its natural target. If you don't want to collect packs and you are looking for a single companion for your weekend long runs as well as your 30 to 60 km races, the 10-liter format is the right compromise. It swallows a waterproof jacket, gloves, a beanie, your nutrition and up to 1.5 liters of water without ever maxing out the volume. For this profile, the Gravity ticks the versatility box better than a 5-liter vest that is too tight or an oversized 15-liter pack.

The trail runner moving into self-sufficiency

When you step up from one-hour runs with aid stations to long formats where you carry everything, the number of pockets becomes decisive. The Gravity packs in storage you can reach on the move, which is reassuring while you learn to manage nutrition and safety gear on the run. The built-in whistle and front reflective details meet race organizers' requirements right away.

The runner looking for the most gear for the money

At €119.95, the Gravity sits below premium options that often top €150, while shipping with two 500 mL soft flasks and a whistle in the box. For runners who want a complete vest without paying the star-brand premium, the math is attractive. It is the right pick if you value what is in the box over the logo.

© Oxsitis, official photo used for editorial purposes

Comfort, bounce and hold

On a trail vest, hold comes before everything else: a pack that bounces ruins a run, no matter how good its fabrics are. The Gravity relies on a medical-grade velcro side closure, adjustable in both length and angle. In practice, you position the straps to match your build instead of living with a single fixed setting. That is the system's main strength: a slim runner and a heavier runner both get a clean, snug fit, which fixed straps don't always deliver.

The short back sits the load a little higher between the shoulder blades, which limits chafing on the lower back and leaves your breathing free. The cut around the shoulders follows your arm swing without creating pressure points. At RunMorph, our takeaway is that a vest tightened at the sides moves less than one tightened only at the chest, and the Gravity puts that principle to good use. The flip side: the velcro takes some getting used to and needs regular cleaning to keep its grip over time.

Compartments and accessibility

This is the Gravity's number one selling point. Up front, you get six zippered stretch pockets with quick access, a water-repellent zippered pocket cut for a smartphone, and two dedicated flask sleeves. That density of storage makes the difference when you need to grab a gel or stash a windbreaker without stopping. The zippered phone pocket is a real plus compared with the simple elastic pockets you see elsewhere.

At the back, the expandable main compartment swallows a jacket, gloves or a hydration bladder. A horizontal quick-access pocket lets you slip in a layer on the fly, while a water-repellent zippered pocket secures keys, papers and phone. The vertical quiver, made from a tough fabric, holds your poles. A detachable velcro panel gives you access to the rear pockets without taking the vest off, a clever detail for solo runners. Overall, the organization is richer than on most vests of this size.

© Oxsitis, official photo used for editorial purposes

Hydration

The Gravity comes with two 500 mL soft flasks, so one liter is instantly available up front, the most practical setup for taking small, regular sips without breaking your rhythm. The angled sleeves make it easy to slot a flask back in after drinking, a point often overlooked on entry-level vests. For longer formats, the back compartment takes a hydration bladder of up to 2 liters, not included, which pushes total capacity past 3 liters if you combine flasks and bladder.

The vest is also compatible with a drinking tube kit sold separately, for runners who prefer sipping from a hose rather than pulling out their flasks. That modularity is a strong point: you adapt your system to distance and temperature instead of being stuck with a single setup. The built-in safety whistle covers one of the mandatory gear items required at most long trail races.

How it stacks up against the competition

In the versatile 10-liter vest segment, the Gravity goes up against three models RunMorph has already reviewed. Against the Kiprun Bag 900 10L (240 g, €80, 1 L bladder included), the Oxsitis is 70 g lighter with better-finished fabrics, but it costs more and ships without a bladder. The Kiprun remains unbeatable on pure value for money, while the Gravity takes the lead on comfort and pocket count.

Against the Compressport Ultrun Evo 10 V2 (114 g, €180), the choice is clear: the Compressport is an ultralight racing weapon built for pure performance, the Gravity is a more versatile training and self-sufficiency vest at a much lower price. Finally, against the Raidlight Ultralight 12L (200 g, €159.90), another French brand, the Gravity offers slightly less volume but a gentler price and a highly adjustable velcro closure, while the Raidlight counts on its Freelock system and its 12 liters. Three philosophies, three budgets, one use case.

Which pack for which distance with RunMorph

You don't choose a vest in the abstract, you choose it for what you actually run. For a 2 to 3 hour long run, the Gravity only needs one liter in the flasks and a light layer: it then carries like a 5-liter vest. For a 40 to 70 km race, you unlock its real potential by adding the bladder and full nutrition. Beyond that, for full-on ultras, we prefer a larger capacity.

Most important of all, train with your vest loaded exactly as you will run on race day. Our RunMorph training plans include progressive long runs that are the perfect opportunity to break in your gear: strap adjustment, flask placement, nutrition management. A vest only becomes comfortable once you have tamed it over several runs.

© Oxsitis, official photo used for editorial purposes

The RunMorph Coach verdict

The Gravity 10L is an excellent all-round vest, likely one of the best choices for amateur trail runners who want a single pack covering 90% of their needs. Its adjustable side closure, wealth of pockets and reasonable price make it a benchmark in the mid-range. Our main criticisms are the lack of a bladder in the box and a velcro closure that needs some upkeep, but nothing that undermines its relevance. If you are new to Oxsitis, it is an excellent entry point into the world of a French specialist that knows exactly what it is doing. RunMorph score: 8.5/10.

Key takeaways for your training

• Real versatility: 10 liters and 170 g cover everything from the long run to a 60 km race, one vest for most of your needs.
• Velcro side closure: adjustable in length and angle, it limits bounce better than a simple chest strap. Test it loaded.
• Dense organization: six zippered front pockets, a water-repellent phone pocket, a pole quiver and rear access without taking the vest off.
• Modular hydration: two 500 mL soft flasks included, compatible with a 2 L bladder and a drinking tube kit to adapt to the distance.
• Gear for the money: €119.95 with flasks and whistle included, below premium models with equivalent contents.