Which Stone Glacier frame is right for you?

We make two ultralight, load-hauling hunting frames: the Krux and the Xcurve. Both frames are compatible with every SG bag (except R3 bags), and each feature adjustable lumbar support and an integrated Load Shelf rated for 150+ pounds.

Although the frames are similar in design, they have one key difference: the Krux Frame features straight carbon stays and the Xcurve Frame features curved carbon stays. This difference accounts for distinctly different back shapes and allows the wearer to achieve a comfortable fit depending on the size of their torso and shape of their back.

Through a decade of fitting individuals into packs, it is our experience that the majority of people prefer the fit of the Krux Frame.

We recommend contacting our customer service team to best help you find the right frame. We also offer free exchanges to ensure you get the right frame. Regardless of which frame you have, the most important factor is to fit your pack properly. Please reference the "SIZING & FITMENT" section on this page for guidance on how to fit your pack.


Krux Frame

  • Our most universally fitting frame
  • Generally fits people with a flatter back and torsos under 19”
  • Generally fits women better than the Xcurve frame

Xcurve Frame

  • Generally fits people with a more pronounced curve to their back, particularly in the lumbar

R3 Frame
The R3 Frame is designed for military applications but is well at home in the mountains. Note that the R3 Frame is only compatible with R3 bags. Likewise, R3 bags are only compatible with the R3 Frame.

  • Generally fits people with a flatter back and torsos under 19”

Terminus Packs
The Terminus packs are our lightest expedition-size packs designed for hunting sheep, goats, and mule deer in the alpine. The fit of these packs is most similar to the Krux frame.


Start by determining the correct waist belt size using your pant waist size to find the corresponding SG frame waist belt size:

  • Small: 28" - 30"
  • Medium: 31"- 36"
  • Large: 37" +

All Stone Glacier frames provide the industry’s most simple and functional torso adjustment, providing micro-adjustability to achieve a perfect fit. When you receive your pack, we recommend that you fit it properly by loading it with 25-35 lbs. to ensure it is comfortable, fits properly, and meets your expectations. There are three things we look for in a perfect pack fit:

pack fit

  1. First, we always want the belt (A) centered on the tip of your hip bone. Belt positioning can be altered by adjusting the attachment height of the shoulder straps. (B)
  2. Next, we want to make sure the shoulder straps make solid contact with the backside of our shoulders. Most gaps between the shoulder strap and shoulder can be eliminated by loosening the load lifters (C).
  3. Lastly, we want to aim for the color transition on the shoulder straps (D) to land on, or close to, your collarbone. Placement can be altered with a combination of adjusting the attachment height of the shoulder straps on the frame sheet and loosening of load lifters.

For step-by-step instructions on how to properly fit your pack, check out this video:


Before you initiate a return or exchange, please call Customer Service first. We are available and happy to help.

You have 30 days from the date of purchase to return any of our products for a full refund or exchange for a different size. Products must still be in a new and resalable condition without any physical damage, stains, etc.