Ok all, here are my thoughts after testing the X-Curve. Bottom line: for me, it's WAY more comfortable for a number of reasons. If you have a flat back keep reading, b/c Kurt mentioned you can put those stays in the new frame, which would be the direction I would go.
Kurt reached out b/c I have had some problems getting the Krux frame to work for me, specifically I have some curve to my back and cannot get more than 1/2 - 1/3 of the lumbar pad to contact my lower back, even with more foam in it. Secondarily, I have about an 18.5" torso so I bottomed out the Krux for adjustability, especially when I get 80 lb +.
Stats: 5'8" 150 lb, have ran the Krux, Kuiu and MR Nice frames, all with animals on my back. I typically train with a backpack once per week with 60-80 lbs hiking, so I feel like I'm fairly in-tune with adjustments, setup and comfort. X-Curve was tested with 80 lbs.
I tried to get a hold of the X-Curve before my big solo Elk trip late in September, which was my 3rd Backpack trip trying to close the deal. I had to take the Krux back and ended up packing another Elk off the mountain for it, which I'm mentioning b/c I received the X-Curve the very next week, so I didn't pack an animal with it, just concrete. But I did do a multi-day hunt with it, so I did get a lot of field time using it with just gear, which did help me form some thoughts. I will focus on the similarities and differences between the two. Here are some thoughts from my notes.
- Overall, huge improvement in how the frame stays parked on my body under load. I very much preferred the new, denser shoulder strap foam and belt configuration, and could really fit it against my back profile well. I was very impressed with how well that hip belt stayed parked on my hips, it didn't budge at all, even when I tried to make it. The reason why is that lumbar pad could get full contact (compared with 1/3 contact on the bottom of the Krux frame pad), and I could cup the hip belt on myself with the dual 1" connections to the frame. Cosmetically, the shoulder straps look much "cleaner" than the Krux frame I have, which is probably because the stiffer foam gives them a little more structure. Same comment on the hip belt.
- By moving the webbing where the shoulder straps slides through/against the frame down, I could actually spread the load on my back much better than with the Krux. I would attribute the stay shape to that as well, as they bend to follow your upper back contour. MR uses flex in their straight stays and the load lifters actually pull/flex the frame over the top of your back to accomplish that same feeling. I always liked that feeling with the MR framed yoke, which does a great job of spreading weight across your whole upper back. I could adjust the X-Curve frame to spread load across my back that same way, which was huge for me, big comfort and stability improvement.
- In the frame video SG released, the hip belt tension by pulling up on there tri-slide that locks it down. They aren't just blowing smoke when they it locks itself down, I couldn't make it slip. I did have some trouble getting out of it, but I didn't try releasing it the way they show in the video. Overall, the forward pull system is quite effective and a welcome change.
- One thing I mentioned to Kurt was my personal preference would be to have a more dense foam on the outer portion of the hip belt still. The dual density foam change on the new belt was a huge improvement for me, and I didn't get the normal hip bruising I get with 80 lbs in the Krux frame. So my preference may be a moot point. Like the shoulder harness, the belt actually looks cleaner too with the stiffer foam. Not getting the bruising was a huge improvement for me compared with the Krux.
- If you are short like me, one thing to keep in mind is with regards to the actual stays - having them bend back over your shoulder was really nice under a big load, and they didn't get in the way with weight in the load shelf and the bag off of the frame. At my height, when I had the sky archer bag on there, it was very restrictive for me while hunting (meaning tipping my head back, or looking at the stay out of the corner of my eye), even with the load lifters very loose. The pic below kind of shows that. For me personally, that's something I can deal with to gain comfort year-round, but I'm still going to mention it b/c I noticed it while testing. I feel like I would need more time tinkering with it in the field to have a complete evaluation of the impact having the frame bend back over your upper back, past vertical. The other thing it shows is how the harness contacts my shoulder blades down my back a lot lower than it ever did with the Krux frame. I like the "MR" way with a little flex to the frame, which adjusts how much you pull across the top of your back.
Overall, this was a HUGE improvement for me. I still find the shape of the newer Mystery Ranch lumbar pad fits into my back a little better (mainly because it isn't as wide and a little taller), but I was also running the 2-1/2 piece of foam lumbar pad, and I usually run a 3-piece foam pad, which may be the difference (the std MR pad is thicker). I didn't get a lot of lumbar pressure under heavy load, and had no slip on the waist belt, so I think Kurt really nailed it on this one.
If anyone has any questions feel free to post or PM me - I know I'm looking forward to thoughts from some of the other guys that ran the frame.
Testing frame with 80lbs
Testing frame in the field
X-Curve shaped stays
I wore out the refresh button the day they were to be released.
