Choosing the right petate (military rucksack) is critical for comfort and load carriage. Unlike civilian backpacks, military rucksacks are designed to carry heavy loads over long distances, and a poor fit can lead to back pain, fatigue, and reduced performance. This guide explains how to measure your torso, select the right volume, and adjust your pack for optimal fit.

Why Sizing Matters

A rucksack that is too long will sit on your hips incorrectly, causing the load to pull you backward. A pack that is too short will not transfer weight to your hips, leaving all the weight on your shoulders. According to the Spanish military, a properly fitted petate should have the hip belt resting on the iliac crest (the top of your hip bones) and the shoulder straps snug but not tight. The load should be carried primarily by the hips, with shoulder straps only stabilizing the pack.

Measuring Your Torso Length

The most important measurement for rucksack sizing is torso length, not height. Torso length is the distance from the C7 vertebra (the bony bump at the base of your neck) to the iliac crest. To measure:

  1. Stand up straight and tilt your head forward to find the prominent bone at the base of your neck (C7).
  2. Place your hands on your hips with thumbs pointing backward; feel for the top of your hip bones (iliac crest).
  3. Have someone measure the distance between these two points along your spine.

Common torso lengths: Short (38-43 cm), Regular (43-48 cm), Long (48-53 cm). Many brands like Tasmanian Tiger, Mil-Tec, and local Spanish brands offer adjustable torso systems.

Rucksack Volume by Mission

Petates are categorized by volume in liters. The Spanish military uses different sizes for different roles:

  • Day packs (20-30 L): For short missions or patrols. Examples: Tasmanian Tiger Patrol Pack 25.
  • Assault packs (30-50 L): For overnight operations. Examples: Mil-Tec Assault Pack 45.
  • Multi-day packs (50-80 L): For extended patrols. Examples: Tasmanian Tiger Mission Pack 70.
  • Expedition packs (80+ L): For long-range reconnaissance. Examples: Mystery Ranch NICE 6500 (106 L).

For civilian hiking, a 50-70 L pack is typical for multi-day trips. The Spanish brand Altus produces the Petate Mochila 70L, priced around €90, popular among reservists.

Adjusting the Fit

Once you have a pack, adjust it in this order:

  1. Loosen all straps.
  2. Put the pack on and fasten the hip belt so it sits on your iliac crest. Tighten until snug.
  3. Tighten the shoulder straps so they follow the contour of your shoulders without gaping. The straps should not pull the pack away from your back.
  4. Adjust the load lifters (top straps that angle from shoulder straps to the top of the pack). They should pull the top of the pack toward your shoulders, not lift it.
  5. Fasten the sternum strap at chest height to keep shoulder straps in place.

If the pack does not fit after adjustments, consider a different size or brand. Many Spanish online retailers like Militar.es and Tienda Militar offer free returns for size exchanges.

Spanish Military Petates

The Spanish Army issues the Petate de Combate (combat rucksack), which is a 60L pack made by Altus or Igan. It features a fixed torso length (regular) and a robust frame. Many surplus stores in Madrid, such as Militaria Madrid (Calle de la Montera), sell these for €50-80. For more modern designs, check our guide on best military rucksacks in Spain.

Buying Online

When buying online, always check the manufacturer's sizing chart. For example, Tasmanian Tiger uses S/M/L based on torso length. Mil-Tec uses one-size-fits-all with adjustable frames. For a comprehensive overview of where to buy, see The Complete Guide to Buying Spanish Military Gear Online.

Common Mistakes

  • Buying based on height. Two people of the same height can have different torso lengths.
  • Overloading. A pack should not exceed 25% of your body weight.
  • Ignoring hip belt padding. A thin hip belt will dig into your hips.
  • Not testing with weight. Always load the pack with 10-15 kg and walk around a store.

In Spain, you can visit physical stores like Decathlon (their Quechua MH500 line is a good entry-level option) or specialty stores like Barrabes in Barcelona.

Conclusion

Choosing the right petate requires measuring your torso, understanding volume needs, and adjusting the pack properly. Take the time to try on packs with weight, and don't hesitate to return if the fit is wrong. A well-fitted rucksack will make your outdoor or tactical activities far more enjoyable.

Related Articles

  • The Complete Guide to Buying Spanish Military Gear Online
  • Best Military Rucksacks in Spain
  • Tactical Gear Maintenance Tips
  • Hiking Essentials for Spain