the OMM Classic 25

the OMM Classic 25 – the backpack that always works

See our entire range from the OMM here!

The OMM Classic 25 is an iconic, high-capacity running backpack , designed for long distances, challenging terrain and multi-day adventures . It combines low weight, extreme durability and smart access on the move – and has been the obvious choice at the start line of Mountain Marathons worldwide for over 50 years.

The Classic range was developed back in 1974 to specifications from Olympic champion and founder of the London Marathon, Sir Chris Brasher . It was the first backpack to seriously consider weight as a crucial feature , and that philosophy lives on in today's version.

In its latest iteration, the Classic 25 perfectly balances lightweight comfort at all speeds, running stability and modular functionality . It's equally at home on an OMM , on races and expeditions like UTMB, Spine Race, Dragon's Back, MDS, Grand-to-Grand, 4 Deserts, Fire & Ice Ultra – or for everyday training and mountain adventures.

This is simply the backpack that does everything right .

Why choose OMM Classic 25?

Designed for ultra-running, mountain running & expeditions

25 liter volume – perfect for long distance and multi-day trips

Extremely stable when running on hilly terrain

Excellent access to equipment while moving

Can be converted from expedition pack to super-fast dash pack

Proven design with decades of racing history

Comfort & carrying system

The Classic 25 is geometrically designed to sit stably when running in the mountains.

EVA padded shoulder straps (closed cell, no side seams)

Follows the body's natural contours for minimal movement

Removable waist belt – shift weight to the hips or remove too little weight

Removable EVA Duomat back cushion that also functions as a 3/4 lying surface

Smart storage solutions

Large stretch mesh pocket on the back – rain jacket, food or water

Mesh side pockets – hold bottles or equipment (even dirty shoes)

Removable lid strap for extra volume in the back pocket

Front waist belt pockets (total 2 L) with key clips & phone slot

UGR – Universal Gear Rail for mounting additional accessories

Attachment points for pole, ice axe or other equipment

Features

EVA padded shoulder harness

UGR – Universal Gear Rail

Large rear mesh pocket

Zippered pockets on lid & belt

Quick release buckles for efficient handling

Removable waist belt pockets

Aluminum tent pegs (double as bottle openers)

Mesh side pockets

Removable Duomat back cushion/sleeping mat

Back length: 45 cm

Technical details

Volume: 25 liters

Material: Nylon, TPU-reinforced nylon, 3D airmesh, stretch mesh

Weight:

• 670 g (fully equipped)
• 365 g (peeled for competition)

Suitable for you as:

Running ultra-marathons or mountain running

Want a backpack that works in all situations?

Prioritizes light weight, stability and reliability

Want to be able to adjust the bag according to distance and season

Looking for a proven classic with modern functionality?

Never tried OMM before or just need a little help finding the right size? You can find size charts and help finding the right fit HERE!