Frame Education

[doverpack12]

I wanted to start a new thread because I haven't seen or read one asking specifically about the differences in frame design. What is the difference between something like a Stone Glacier Krux, Kuiu Ultra, Kifaru Bikini, and EXO frame? I don't want to hear about durability or opinions on any of the listed companies or bags.

From what I can tell and read here is what I make of each one.

Stone Glacier - Little if any contour built into frame and pretty straight vertically. I can't tell if the lower part of the stays have some contour built in or not but I'm pretty sure the top is straight. Advantages and Disadvantages?

KUIU - Pretty much like the Stone Glacier but the bottom has a slight bend away from the belt and harness to match the lumbar curve. Advantages and Disadvantages?

Kifaru Bikini - two options with the aluminum stays or molded carbon fiber both have lumbar curve and then also curve toward the wearer behind the shoulders and then reverse curve away from the wearer near the top for the load lifter attachment. Advantages and Disadvantages?

EXO - lumbar curve with reverse curve to provide shoulder room and then straightens at the top with not much reverse curve for the load lifters but the frame has a bend away horizontally right behind the head to provide a little room there. Advantages and Disadvantages?

So what are the advantages and disadvantages of each type of frame. I currently have a pack and frame which if I lean forward and to the side slides around right behind my shoulder blades and would like to make the right decision on which direction to go from here with the frame.

 

[doverpack12]

Let's add Paradox to the discussion

 

[Yellowknife]

Stone Glacier - Little if any contour built into frame and pretty straight vertically. I can't tell if the lower part of the stays have some contour built in or not but I'm pretty sure the top is straight. Advantages and Disadvantages?

The SG uses straight carbon fiber rods (roughly 1/4" in dia) for the frame structure, so there is no curve form at all. Like most of the rest of the packs you mention, it actually contacts the body only at the lumbar and for a short distance in the upper back area.

With the 3-pc belt, the lumbar pad is wedge shaped to make up for the lack of frame curve. It also has horizontal plastic stiffener wings at the bottom of the frame to spread the load along the belt and avoid point loading the lumber area. Works fine for me.

The straight frame does have less contact with the upper back than a curved frame, but the way SG shoulder straps should be fitted is with 100% contact. i.e. you shouldn't reef on the load lifters hard enough to pull the shoulder straps away from your back. With the straps wrapping up and over the shoulders combined with good load lifters, everything is solid and well stabilized without having the crank on anything excessively and the the amount of frame contact isn't particularly important.

Here's what it looks like loaded down. No side to side sway in the pack frame at all. Wish I could have said the same about the packer!



I'm not sure about any significant advantages/disadvantages to the straight vs. curved frames when properly set up, but I know that straight works fine and so have the curved frames I've used. The way the hipbelt is attached and the harness is constructed have seemed more important to making it work out.

Yk

 

[fillthefreezer]

interesting. would love to see if patrick and kurt have anything to add on the topic

 

[JDZ]

Good topic. I've never actually seen a good picture showing the makeup of the Stone Glacier Krux frame. Just the one on their website, which is tough to see what's going on.

 

[Yellowknife]

Good topic. I've never actually seen a good picture showing the makeup of the Stone Glacier Krux frame. Just the one on their website, which is tough to see what's going on.

Here is a photo of the back side of a SG frame. Barneys frame on the left for reference.



It basically consists of four solid carbon rods. Two upright on either side about 9" apart, and two in an X configuration. They fit into sleeves sewn into an xpac fabric envelope and are removable from the bottom. The rods aren't connected in any way, but just fit into pockets at the ends. The whole thing can flex a bit in torsion, but you can't stuff it full enough to make it barrel, and of course it's vertically very stiff.

Like I said before, the bottom has stiffened "wings" that come off both sides several inches along the waistbelt to spread the weight.

The harness side is even more basic. Just two straps held on by velcro, and a fairly simple removable waistbelt. Not much complicated about the SG packs.



Yk

 

[JDZ]

Thanks Yk. How does the SG belt attach to the frame? Any photos that can show the attachment well?

 

[doverpack12]

Thanks YK that is just the type of information I was hoping to acquire through this thread

 

[Jager]

Of the packs you've mentioned I have only tried the Kifaru and the Kuiu Icon.

The Bikini for me, rides well, with the curved stays fitting in nicely. Advantages, well, fits well and is comfortable keeping enough rearward head movement possible.

The Icon, well, not having tried a SC it is hard to compare the two, except, when you look at YK's frame pic, there is very little similarity. The Icon is 1 complete carbon fibre sheet. Advantages, when you snig the load lifters tight the frame does take on the shape of your back quiet readily. Disadvantages, it is not very durable, the curve away at the bottom tends to pull the buckle point of the waistbelt back into you when pulling the load lifters tight. The design of the shoulder strap attachment points don't allow them to sit flat on your shoulders, tilting them outwards.

Hope this helps somewhat.

 

[Kevin_t]

The Paradox has some lumbar curve and some shoulder curve , however more than anything it wraps around your body down low and spreads load close to the illiacs. The top of the frame is somewhat narrow and non intrusive as well. The center of gravity and load control are very good IMO.

 

[RockChucker30]

I build the Paradox frames, so I'll kick in my $.02

Starting at the top, our frame has a long radius sweeping bend for the shoulders, then reverses to hug the lumbar, then bends back out and around to make room for the upper glutes. The frame does a really good job of hugging the body, and getting weight tight to your center of gravity. The frame has a joint in the bottom that allows the two sides to move independently of each other....this makes it feel like a daypack with 15 lbs, but the vertical strength is still there to comfortably support heavy weights.

As far as strength goes, it'll handle any weight you can, up to 150+ lbs.

The shape of the frame helps the pack ride comfortably, but IMO more important is how the belt load transfers, and having a belt that never slips under even ridiculous loads.