Internal Frame Backpacks vs Frame Stays: Which is Improved?


When deciding upon in between lightweight multi-day backpacks, which is much better: a backpack with an internal frame or one particular with frame stays? It is a query that confuses a lot of backpackers who want to lighten their backpack weight but want to retain the comfort and load-carrying skills that an internal frame backpack gives.

In a lot of situations, backpacks with frame stays will be as great as these with complete backpack frames, offered you are carrying loads beneath 30 pounds. But there are so a lot of distinct kinds of backpack frames accessible now, that it is complicated to make a blanket comparison like this devoid of understanding how internal backpack frames operate and the strengths and weaknesses of distinct frame kinds. That way you can decided for your self.

Backpack Frames 101

There are a wide wide variety of frames utilized in internal frame backpacks. Some are uncomplicated sheets of plastic or wood, some are 360-degree wire loops, U-shaped loops, wishbone-shaped, or strips of vertical and horizontal metal that have been welded with each other into a reinforced cage.

In spite of these kind element variations, all internal backpack frames serve a popular set of functions:

  1. Defend your back from the contents of the pack’s bag (back protection).
  2. Avoid the pack bag from collapsing on itself when it is loaded (backpack shape)
  3. Aid transfer load to a hip belt, if your pack has one particular (load transfer)
  4. Offer an anchor for load lifters, if your pack has them (load lifters)

1. Back Protection

The contents of your backpack can trigger discomfort if they poke you in the back or “barrel” into it. For instance, if you carry a tough bear canister inside your backpack, a great frame will avert its edges from poking into your back. The exact same holds for barreling, exactly where an overstuffed pack bag types a curved and tough barrel shape that can press down on your spine, generating it uncomfortable to carry. A backpack frame can shield your back by forming a tough barrier against these objects or by developing a gap in between your back and the pack bag to avert any discomfort.

two. Backpack Shape

A backpack frame assists keep the shape of your backpack and its height when you load it up. If you didn’t have a frame, your pack bag would just be a shapeless cloth sack that would fall more than on itself when you fill it up. But getting a frame assists preserve its shape and tends to make it a lot easier to pack or uncover stuff in the pack. A backpack frame also assists preserve the torso length of a backpack, which is one particular of the important determinants of a effectively-fitting backpack. With no a frame, the torso length of a backpack shortens when it collapses on itself.

three. Load Transfer

A backpack frame will assistance transfer the weight of your backpack onto a hip belt if the frame is connected to it. Most internal frames slot into a hip belt or the hip belt is attached to the sides of the frame, which is popular on a lot of ventilated backpacks. Either way, gravity forces the load down onto your hips, which is what you want if you are carrying a lot more than 20 pounds since your legs are the strongest muscle tissues in your physique.

four. Load Lifters

Load lifters are created to tilt a backpack frame forward slightly to transfer a lot more of a pack’s weight onto your hips and off your shoulders. Load lifters have to be anchored to the best of a backpack frame, preferably a horizontal anchor, to achieve this and not the pack bag itself.

Internal Backpack Frame Examples

Right here are some distinct kinds of backpack frames to give you a much better really feel for how they operate and their strengths and weaknesses vis-a-vis these 4 functions.


Examples for framesheets
The Mountainsmith Zerk 40 (left) has a soft foam frame sheet, even though the Granite Gear Crown2 38 (suitable) has a thin and versatile plastic framesheet

Some producers use lightweight and versatile foam, plastic, composites, or even wooden sheets as frames. These deliver varying degrees of backpack protection based on how stiff they are. Foam framesheets and thin plastic framesheets can be quite ineffective on that score, though they can assistance develop a backpack shape that is a lot easier to pack and does not collapse on itself. Their load transfer skills and load lifter effectiveness rely on how stiff they are, which is why you commonly uncover them utilized for backpacks created to carry lighter loads. Stiffer framesheets are much better for carrying a lot more weight, but they’re normally substantially heavier.

Wire Perimeter Frames

The Osprey Exos (left) and Osprey Levity (suitable) have wire perimeter frames that allow ventilation cavities

Wire perimeter frames are typically identified on ventilated backpacks like the Osprey Exos, Osprey Atmos AG, or the Gregory Zulu. They’re metal rods that have been bent into a curved 360-degree shape, generating it doable to develop a cavity behind your back so air can flow by way of. They’re quite rigid and have horizontal anchor points on the best and bottom of the frame, with a cross-bar for anchoring the shoulder straps. They deliver great back protection considering that your back has an air cavity behind it and does not touch the pack bag, and they deliver fantastic load transfer considering that hip belts and load lifters are can be attached to the side or best of the frame. But these ventilation cavities can intrude into the pack bag, minimizing their volume, and generating it tough to uncover things packed in them.

Tubular frames

The Gossamer Gear Gorilla 40 (left) and Sierra Styles Flex Capacitor 40-60 (suitable) have tubular frames that are held firmly in location inside their pack bags.

Tubular frames can be really lightweight and rigid, especially if they’re fitted quite tightly into a pack and slot down into the hip belt.  Even though tubular frames are equivalent to wire perimeter frames in look, they do not kind a total 360-degree loop. Tubular frames differ extensively, having said that, as you can see from these examples. Comfort-smart, they’re great at stopping barreling but are normally augmented with padding sewn into the pack bag or inserted into a pocket to avert sharp objects from poking customers in the back. Otherwise, they’re great at stopping the backpack from collapsing on itself, they make it a lot easier to pack and uncover stuff inside, they transfer weight to a hip belt if they’re connected straight to it, and can deliver an anchor point for load lifters based on how they’re oriented.

The 3400 has two aluminium frame stays that slot into stay pockets behind the shoulders
Most Hyperlite Mountain Gear backpacks have two aluminum frame stays that slot into keep pockets behind the shoulders. Their bigger volume 4400 and 5400 cubic inch backpacks also incorporate a sewn-in foam pad for added comfort and protection.

Frame Stays

Frame stays are vertical strips of aluminum or carbon fiber that are inserted into lengthy pockets inside a backpack and behind your back. Most backpacks that use frame stays will use one particular central keep or two side by side stays. They’re normally pre-shaped to match the curve of your back though they can be bent additional to match your physique shape.

Frame stays are usually utilized by ultralight or lightweight backpack producers that concentrate on promoting backpacks to customers who are carrying 30 pounds of weight or significantly less. The argument has often been that you do not will need a heavy and rigid frame for carrying a 20-30 pound load and there is some truth to that, though it varies by backpack and what you have to carry inside of it.

Even though frame stays deliver your back with some protection from a pack’s contents, that is not their greatest strength. Their principal function is to keep a backpack’s shape and avert the torso length from collapsing when you load it up. They will also assistance with load transfer if they slot into a pack’s hipbelt, preferably a hip belt that is sewn onto the pack bag. Lots of backpacks that use frame stays do not have load lifter straps since they’re not deemed important on a lightweight backpack or there’s no strong location to anchor them on the pack.

The Catalyst has two pre-bent aluminum stays that terminate in the packs lumbar pad. They're accessible inside the main compartment so you can shape them further if you need a more personalized fit.
The Catalyst has two pre-bent aluminum stays that terminate in the pack’s lumbar pad fitted to a foam panel for enhanced comfort and back protection. They’re accessible inside the primary compartment so you can shape them additional if you will need a a lot more customized match.

Some pack makers will combine a foam or plastic framesheet and a frame keep with each other to complement every single other. That is a great way to combine the rewards of each in a backpack. For instance, the ULA Catalyst which can carry 40 pounds loads, has a frame consisting of two frame stays for added stiffness and load transfer, combined with a foam pad for enhanced comfort.


Frame stays can deliver a lot of of the exact same functions as an internal frame backpack for lighter loads in between 20 and 30 pounds, and in some situations even larger. For instance, they can deliver protection for your back from sharp-angled objects like the sides of a bear canister or cookpot, though this capacity is enhanced when they’re combined with a framesheet produced with foam or tough plastic. Frame stays also assistance stiffen a backpack so it maintains its length and shape when loaded. They can also help in load transfer to a hip belt if they connect straight to it and the hip belt is rigid sufficient to deal with the weight, but could have restricted utility as load lifter anchors based on how they’re positioned on a backpack.

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