Gravity Back Base



Back protector designed for mountain biking, skiing, snowboarding and other action sports. Optimal safety with integrated removable protection. Based on the Switch Element System concept.

How to choose my backrest base



Gravity Back Base

The back structure is the essence of our Switch Element System concept. It has been developed with the highest standards of an ergonomic engineer to provide the best possible fit and comfort.

A special YKK zip makes it possible to combine the back structure and the PRISM volume of your choice in a flash. No matter which volume is zipped onto this base, the PRISM backpack provides maximum support on the back. The backpack does not move and can be forgotten as it becomes one with the user.
The backpack base is supplied with a removable EN-1621-2 level 1 protection. The flexible back protector ensures optimal protection while remaining very light for the committed sportsman.

S/M : Taille <1m70 (buste entre 34 et 43 cms) – Réf: D00001
L/XL : Taille >1m70 (buste entre 44 et 56 cms) – Réf: D00002

Technical specifications of the Backbone

  • Sizes: S/M and L/XL
  • Dimensions: 54cm x 28cm x 5cm
  • Weight: base + back protector = 815g
  • Composition: Nylon 210D R/S PU3 / N190 Taffeta
  • Colour: Grey Iron / Grey Storm

Equipment of the Gravity Back Base

  • Adjustable chest belt with 4 attachment levels
  • Straps adaptable to male and female body shapes
  • Wide waist belt for hip carry and upper body freedom of movement
  • Space for a water bag
  • Waist belt for full back protection
  • Compatible with all water bags (up to 3 litres)

Summer volumes available as an option:

Winter volumes available as an option:

Optional equipment holders available:


This single colour backpack (blue-grey) can be combined with different coloured volumes and helmet holders, making it a unique and customised bag. Make your choice on our website shop or visit your nearest PRISM dealer.


This product has a 10 year warranty

Further information


L/XL : Taille >1m70 (buste entre 44 et 56cm), S/M : Taille <1m70 (buste entre 34 et 43cm)


Mountaineering, Climbing, Motorcycle, Hiking, Snowshoeing, Skiing, Snowboarding, Urban, Mountain biking, Electrically assisted mountain biking


Androgynous: Ergonomic straps and waist belt, made of reinforced foam, whose ergonomics have been studied to adapt to both male and female morphologies.

Anti Spine-Blaster (ASB): Removable back protection. CE certified, EN 1621-2, motorbike standard. Weight: 300g.

ASB Pocket: Slot for removable back protector.

Comfy Paddy: 6 back pads and 2 lumbar pads to ensure maximum wearing comfort and perfect adhesion to the back, while allowing air to circulate.

Skinny Pock: Zipped pocket on the waistband so that nothing can stick out and catch on the branches.

Stern Sliders: 4 levels of chest strap adjustment: piping + metal buckle.

Water Hole: Opening for the pipette outlet.

Water Tray: Slot for hydration system - up to 3L - with 3 Velcro straps to accommodate any type of water bag (not included).

Zip Fit Half: Specific YKK zipper to join the back base and the PRISM Zip-On of your choice.

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