Custom hipbelt – source?

[John M]

Thanks folks.  I appreciate the many helpful comments.  Based on what I’ve learned I’m going to change what I have planned and make something more like divide hip belt.

I’ve been reading up on the divide and haven’t been able to tell how the shoulder harness attaches since the frame has no cross member up high.  Can anyone explain it?

 

[Link .]

. DAVE CHENAULT would be the best person to ask he worked for them and he has numerous blog posts on his blog BEDROCKANDPARADOX including his DIY posts The future of ultralight backpacks  or The big pack and others LUKE SCHMIDT did a BPL article based on Dave’s posts on his site DIY ULTRALIGHT BACKPACK: MY SEARCH FOR A PERFECT PACK some of this may interest you, I don’t know

[John M]

Thanks I appreciate the response. I’ve looked at every one of those links previously and found no details regarding how the shoulder harness attaches to the frame.  Maybe I missed it but I didn’t see it.

 

[Link .]

Did you try talking to Dave who worked for Seek Outside?

[John M]

No, I didn’t talk with Dave.  I figured it out though.  Seek Outside has a video that shows how to adjust the suspension and you can see how it’s put together from that.

 

[Luke F]

I find plastic stiffening in a belt only makes sense when the frame-to-belt transfer point is very narrow, like some traditional internal frames, or something like the Exped lightening, The Seek Outside belt like many external frames depends on a much wider transfer point that allows for a very soft belt. Of course the plastic is a gamble as some stiff belts are comfortable while others are not, for instance the older Arcteryx Bora/ILBE belts are stiff in the very wrong shape for me and I find miserable.

You can actually bolt an SO belt to a Jansport Scout frame with zero modifications.

[John M]

I have not had the opportunity to look at a divide first hand but I believe that the divide hip belt is attached by two straps.  The pack hangs from those straps – that’s a narrow attach point in my book.  Actually, I already know that the SO belt would be an easy bolt up to the Jansport frame.  I’m a big guy and their XL belt is too short for me.  I contacted SO and they schooled me in why they wont make me a slightly longer belt.  It has to do with making money and profitability.  I would love to just buy something and bolt it on but I’ve done my research and I don’t believe that item exists.  I need a 38 inch padded portion.  ULA sells that but their hipbelt is not really up to a 50 lb load (my design goal) when most of the load will be transferred by the hip belt.

Anyhow, this is why I started this thread – to maybe learn about an option that I didn’t know about.

[Luke F]

The frame to belt transfer on an SO belt is about 11-12″ wide, hard to get wider then that without going to the old jansport “hipbeater” belts, if that is your idea of narrow I don’t know what wide is. Most internal frames transfer in about 6″ or less depending on stay or lumbar pad width.

[John M]

I believe we are talking about 2 different things.  Unfortunately I don’t have an SO divide to examine. I’m talking about the attach point of the strap/belt interface not the strap/frame interface.   As I understand it from the pictures I’ve seen, the load is transferred from the belt into the frame through 2 straps.  The straps look like they are about an inch wide or maybe a little less.  All of the load has to go through those straps into the frame no matter how far apart the straps are placed.  So half of that load (if you’re standing still) goes through  each strap into the belt. That can be a lot of load to dump into foam alone.  A thin piece of plastic inside the belt aids in the load transfer.  Adding some reinforcing fabric to the belt could also do it .   I’m not being critical of their design because I haven’t even seen it first hand.  I want to make something that works on the first try and I have limited resources.  I would buy one of their belts if they would make  one for me with the padded portion 2 inches longer but they told me that they no longer do custom work.

I’ve designed structures my entire working career. Load transfer and providing an acceptable load path is a basic structural concept.  You can’t dump a lot of load in a concentrated area without reinforcing it in some way.  The strap/belt interface is a fairly concentrated area.  Their belt probably has some reinforcement where the straps attach to the belt and its probably internal so it doesn’t show in the pictures.  That said there aren’t that many pictures out there available to examine the details.

[Luke F]

I can assure you the belt has no internal reinforcements and I can assure you they aren’t needed. I don’t know how to describe the mechanics well, but I’d say the best way is that the fabric tension as well as the continuation of the webbing to the shoulder straps balance things out so that the foam or belt does not collapse.

[John M]

That makes sense.  Like I said, I don’t have one to examine and I’ve found only a few limited pictures.

[John M]

Luke F.  you convinced me with your information that I would be best served by purchasing a seek outside belt.  It will be a little short (about 2 inches) but it will definitely work for my project and I can always use it as a pattern for a belt which will fit my waist size “perfectly” some time in the future.

[John M]

I went ahead and bought the hipbelt from seekoutside.  Absurdly expensive in my opinion but my best option.  Shipping was also absurdly expensive.    Around $15 was the cheapest shipping option.  The belt is fairly light and fairly compact and I don’t need it in a few days.  There is no reason shipping should cost that much.

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