K4 % Improvement vs K3

[rclouse79]

According to my last calculation, to three significant figures, it was a 35.7% improvement.

 

[TimeOnTarget]

I was one of the few who didn’t like the k3 at all. I never could make it comfortable. I had a k1 Gen2 before the k3 and found myself wishing I still had it every time I put the k3 on. I even tried to buy it back but the guy wouldn't sell it back to me.

All the above said, I absolutely loved my k4 from the first day I put it on. I don’t know what makes it so different from the k3 but literally no comparison in my case.

 

[ORhunter74]

While I have yet to carry heavy weight in my k4, I can say I like it more than the k3. I’ve got a late season muzzleloader deer tag for next month so I’m pretty sure I’ll be able to test the weight carrying comfort then. And hopefully during coast bull elk season as well.

 

[Maverick1]

After rigorous scientific testing, the lab determined the new K4 to be better than the K3 as per the following complex exponential equation:

 

[Maverick1]

According to my last calculation, to three significant figures, it was a 35.7% improvement.

OK, smarta$$. You need to show your work to receive full credit.

 

[rclouse79]

OK, smarta$$. You need to show your work to receive full credit.

It might be over the head of my audience. I used quite a bit of calculus.
To be honest, I never owned the k3. My old pack was from another awesome company and I loved it. I finally wore it out and like the k4 better in every way.

 

[ORhunter74]

You guys are making my head hurt.

 

[goathunter.oregon]

I'm reviving this thread 18 months later as I'm thinking about upgrading from K3 to K4. If you upgraded from the K3, what's your verdict on the K4?

I like my K3 better than any other pack I've owned, but I do wrestle with the hip belt slipping (despite cranking down the tightness). Others have mentioned that the hip belt is less prone to slip on the K4 and that would be enough for me to justify the cost of upgrading.

One thing I'm wondering is if my tripod will be too long for the internal side pockets of the K4? I have a Tricer-AD (23" long) and in the external pockets of the K3, the tripod head sits above the top of the pocket.

 

[JNDEER]

I'm reviving this thread 18 months later as I'm thinking about upgrading from K3 to K4. If you upgraded from the K3, what's your verdict on the K4?

I like my K3 better than any other pack I've owned, but I do wrestle with the hip belt slipping (despite cranking down the tightness). Others have mentioned that the hip belt is less prone to slip on the K4 and that would be enough for me to justify the cost of upgrading.

One thing I'm wondering is if my tripod will be too long for the internal side pockets of the K4? I have a Tricer-AD (23" long) and in the external pockets of the K3, the tripod head sits above the top of the pocket.

K3 to a K4 is a no brainer- IMO. K4 is a huge upgrade for me- especially regarding the hip belt.

I have a pro master 525C and opened it to 23.5” including a Tricer LP head. It fits in my 3600 side pocket. It is a little snug.

 

[sivart]

I'm one of the few that actually prefers the K3 belt. I could not get the K4 belt comfortable for me. I have boney hip pointers. K4 would actually bruise my hips. The K4 belt is a lot stiffer than the K3. I ended up getting a spare K3 in case I wear out my original. which I will......

 

[cuerro viejo]

I'm reviving this thread 18 months later as I'm thinking about upgrading from K3 to K4. If you upgraded from the K3, what's your verdict on the K4?

I like my K3 better than any other pack I've owned, but I do wrestle with the hip belt slipping (despite cranking down the tightness). Others have mentioned that the hip belt is less prone to slip on the K4 and that would be enough for me to justify the cost of upgrading.

One thing I'm wondering is if my tripod will be too long for the internal side pockets of the K4? I have a Tricer-AD (23" long) and in the external pockets of the K3, the tripod head sits above the top of the pocket.

Prefer k4 belt has it slips less, but I do greatly prefer the k3 bag attachment.

Not the AD but I do run Tricer -BC on outside pocket , swaro 65 STS in other side inside sleeve. If I'm being lazy, I stick spotter w/ tripod out back side of lid, and put one center strap over legs.

 

[rakusak]

Helpful advise for sure! I have a Kifaru setup, but might look at at least a K3 or K4 pack to add to the Arc Frame.

 

[wh0cansay]

I'm reviving this thread 18 months later as I'm thinking about upgrading from K3 to K4. If you upgraded from the K3, what's your verdict on the K4?

I like my K3 better than any other pack I've owned, but I do wrestle with the hip belt slipping (despite cranking down the tightness). Others have mentioned that the hip belt is less prone to slip on the K4 and that would be enough for me to justify the cost of upgrading.

One thing I'm wondering is if my tripod will be too long for the internal side pockets of the K4? I have a Tricer-AD (23" long) and in the external pockets of the K3, the tripod head sits above the top of the pocket.

Slippage is generally caused by a mismatch between the curvature of the frame and the curvature of your spine, as this prevents efficient load transfer to your pelvic region.

Simply changing belts is not a very reliable fix for this - thankfully, the actual fix is fairly simple and cheap. It involves swapping out the rigid composite stays that come with the frame for 7075-grade aluminum ones that you bend to match the shape of your spine, especially in the lumbar area.

There is a chance that the stock bend in the K4 stays fits you better than the K3 one, but again, this is a gamble and it could just as easily go the other way.

Cutting down the lumbar pad or swapping it out for a thinner one is generally also a good idea as this places the load closer to your center of gravity, further reducing the chances of slippage occurring.

The entire reason lumbar pads are so absurdly thick these days is to offset a poor fit caused by the switch from pliable aluminum to rigid composite / carbon materials.

 

[rakusak]

I have a fairly thick piece of aluminum stay in my Kifaru quarter panel frame. I didn’t think it was bendable, but I suppose I’ll give it a try.

 

[wh0cansay]

I have a fairly thick piece of aluminum stay in my Kifaru quarter panel frame. I didn’t think it was bendable, but I suppose I’ll give it a try.

You will need two full-length stays that are identical in width and length to the composite stays in the Exo frame. 7075-grade aluminum can be bent but it takes some effort. I bend them over my leg for the big bends, and use a vise (or park bench) for smaller adjustments. Random picture to give you an idea of what these things look like in the flesh:

 

[rakusak]

You will need two full-length stays that are identical in width and length to the composite stays in the Exo frame. 7075-grade aluminum can be bent but it takes some effort. I bend them over my leg for the big bends, and use a vice (or park bench) for smaller adjustments. Random picture to give you an idea of what these things look like in the flesh:

View attachment 873058

Awesome, thanks!

 

[Mitchynick7]

I’m in the business for my first frame pack as I’m getting into more remote situations and definitely going to be doing some western hunts. This forum and feed is helpful. Thank you for your experience. Are we saying that the k3 if fit correctly shouldn’t have any slippage? I’m not sure I can afford a new bag and K3s still sound incredible.

 

[wh0cansay]

I’m in the business for my first frame pack as I’m getting into more remote situations and definitely going to be doing some western hunts. This forum and feed is helpful. Thank you for your experience. Are we saying that the k3 if fit correctly shouldn’t have any slippage? I’m not sure I can afford a new bag and K3s still sound incredible.

Any pack, if fitted correctly, shouldn't cause slippage. The problem is that many packs don't allow for a proper fit because they come with carbon / composite frame stays that can not be bent to match the curvature of your spine. When the curvature of your frame doesn't match the curvature of your lumbar area, you don't get efficient load transfer to the pelvic area, resulting in slippage. Replacing these stays with 7075-grade aluminum ones will take care of that part of the equation.

Excessively thick lumbar pads exacerbate the slippage issue by placing the load further away from your center of gravity. Contrary to what most people believe, thick padding is generally only a good idea on the hip belt. Padding on the harness and lumbar pad should be minimal.

If you're looking for a pack I strongly recommend trying to hunt down a second-hand Hill People Gear Decker / Decker Tall (external) / Qui-Ya v2 (internal). Their suspension is the best on the market in my opinion, and at a reasonable price compared to Kifaru, for example. Aluminum stays, incredible yoke-style harness, minimal padding, adjustable padding in the belt. Very solid company.

 

[MT_Wyatt]

Any pack, if fitted correctly, shouldn't cause slippage. The problem is that many packs don't allow for a proper fit because they come with carbon / composite frame stays that can not be bent to match the curvature of your spine. When the curvature of your frame doesn't match the curvature of your lumbar area, you don't get efficient load transfer to the pelvic area, resulting in slippage. Replacing these stays with 7075-grade aluminum ones will take care of that part of the equation.

Excessively thick lumbar pads exacerbate the slippage issue by placing the load further away from your center of gravity. Contrary to what most people believe, thick padding is generally only a good idea on the hip belt. Padding on the harness and lumbar pad should be minimal.

If you're looking for a pack I strongly recommend trying to hunt down a second-hand Hill People Gear Decker / Decker Tall (external) / Qui-Ya v2 (internal). Their suspension is the best on the market in my opinion, and at a reasonable price compared to Kifaru, for example. Aluminum stays, incredible yoke-style harness, minimal padding, adjustable padding in the belt. Very solid company.

Minimal padding on lumbar under heavy loads would concern me, but I have a curved back. Using dual density foam with a softer and denser portion allows for comfort while having something more robust under load. I’d agree that just adding addition foam to soak up space along your spine can result in some leverage - but we’re talking about less than an inch.

One thing about the non-adjustable carbon stays: the profiles are typically set to fit “most” or the average of the masses. Foam is compressed to soak up differences. Stay length as an option is a customization that does not get brought up enough. Aluminum is truly customizable to the person in terms of profile - if you know what you’re doing. From a business perspective, that’s a bit of a risk, as is adding weight to the system.

I’m not saying aluminum is wrong; but I think steering people that direction only, especially if not an experienced user capable of mod’ing their own gear, can be.

With regards to slippage and K3 vs K4: exo markets and shows the design evolution to combat slippage…..it’s pretty interesting how that was tested and plays into the lumbar, hip belt shape, etc. I’ve used a lot of different packs, and none have stayed “parked” so well under weight.

K4 Pack Systems — Behind the Design

Before there were K4 Pack Systems, there were countless ideas, prototypes, and tests. Before we put 150 prototypes of K4 Packs in the hands of hunters in 2022, we hiked thousands of miles and hunted across the country in 2020 and 2021 to test new materials, new ideas, and new designs. Here is a...

exomtngear.com

 

[gentileod]

Minimal padding on lumbar under heavy loads would concern me, but I have a curved back. Using dual density foam with a softer and denser portion allows for comfort while having something more robust under load. I’d agree that just adding addition foam to soak up space along your spine can result in some leverage - but we’re talking about less than an inch.

One thing about the non-adjustable carbon stays: the profiles are typically set to fit “most” or the average of the masses. Foam is compressed to soak up differences. Stay length as an option is a customization that does not get brought up enough. Aluminum is truly customizable to the person in terms of profile - if you know what you’re doing. From a business perspective, that’s a bit of a risk, as is adding weight to the system.

I’m not saying aluminum is wrong; but I think steering people that direction only, especially if not an experienced user capable of mod’ing their own gear, can be.

With regards to slippage and K3 vs K4: exo markets and shows the design evolution to combat slippage…..it’s pretty interesting how that was tested and plays into the lumbar, hip belt shape, etc. I’ve used a lot of different packs, and none have stayed “parked” so well under weight.

K4 Pack Systems — Behind the Design

Before there were K4 Pack Systems, there were countless ideas, prototypes, and tests. Before we put 150 prototypes of K4 Packs in the hands of hunters in 2022, we hiked thousands of miles and hunted across the country in 2020 and 2021 to test new materials, new ideas, and new designs. Here is a...

exomtngear.com

I’m in the business for my first frame pack as I’m getting into more remote situations and definitely going to be doing some western hunts. This forum and feed is helpful. Thank you for your experience. Are we saying that the k3 if fit correctly shouldn’t have any slippage? I’m not sure I can afford a new bag and K3s still sound incredible.

I’ve had a K3 for five years. Fought with it the whole time. Called XO and they “sold” me a pad to remedy a defective product. That didn’t work either. Not giving them my business anymore. Went to Eberlestock to solve my slipping pack problem.