Welcome to the "WHY DO WE?" video series.
Every stitch and square inch of our K4 Packs are designed on purpose and built for a purpose. The videos in this series will go behind the design to explain why we build our packs the way we do.
In this video, we explain why we offer the K4 Frame in 4 heights, how to choose the best frame height for your build, and how to change or customize your frame height.
Pack performance begins and ends with fit.
A well-designed pack that offers the sizing and adjustment to fit YOU will provide comfort and mobility with light loads, and excellent performance with heavy loads.
With the correct frame height selected and the pack adjusted properly, the top of the frame should be 2-4” above your shoulder. This creates a positive angle for the load-lifters, which enables them to do their job of “lifting” the shoulder harness minimizing how much weight is carried on the shoulders.
(This is only possible when the hipbelt is designed well and fitted properly, as we discussed in the previous Why Do We? video.)
The positive angle of the load-lifters is important, but there is a point of diminishing returns. If a frame is too tall, you will lose mobility for stalking, ducking, crawling, and glassing uphill. Additionally, more angle in the load-lifters doesn’t always equate to better performance; once you have enough frame height for the load-lifters to perform well, more height won’t necessarily equal more comfort.
In the photo above, Mark is using the K4 Frame with 26.5" frame stays while packing out a Mountain Goat in Alaska. This is a heavy load, of roughly 80-90lbs, and you can see that Mark has a great load-lifter angle. He would also have an effective load-lifter angle with 25" stays, but due to the reduced angle and leverage, he would feel a higher percentage of the weight on his shoulders. For Mark's height (6' 2") and torso length, you can see that the 23.5" and 22" frames would not provide a functional load-lifter angle.
Frame Height Misconceptions
Pack frames that are offered in one height may not fit you well, even if those frames have an adjustable torso range.
Changing the torso setting does not change how tall the frame sits above your shoulder.
To understand this, think of the pack from the bottom up, not the top down.
If the pack’s hipbelt is positioned in the same place every time, and thus the bottom of the frame is at the same point, then the top of the frame will extend upward from that point by however long the frame is. However...
Look at the radically different load-lifter angle in the photos above. Believe it or not, the customer is wearing the exact same frame in both photos. The reason the frame looks so different in each photo is because the customer was wearing the hipbelt too low in the photo on the left, and was wearing the hipbelt too high in the photo on the right.
These photos illustrate why hipbelt position is the critical first step in pack fitting.
K4 Frame Height Options
The K4 Frame is offered in 4 heights — 22”, 23.5”, 25”, and 26.5”.
So whether you are a 5-foot tall lady in our women’s pack, or you stand more than 6’ 2” tall and need our longest 26.5” frame stays, we have a K4 Frame to fit YOU.
Selecting your frame size is mostly based on your height, but choosing a frame height isn’t always a black-and-white, right-or-wrong choice.
Be sure to review our detailed size selection information. If you have any questions or want to chat through the pros and cons of frame height options for where and how you hunt, reach out and we will be glad to help.
We sell frame stay sets, giving you the option to own two different lengths. And you can also cut our frame stays to truly customize your fit.
Is Your Height Right?
We truly want you to get the best fit and performance from your Exo pack, so once you have loaded your pack with some weight and followed our fitting process, feel free to send photos of you wearing the loaded pack to us. We will verify your fit and, if needed, let you know how to make any changes. Here are some “before and after” examples from our customers.