Hipbelt and Suspension

David,

My current pack utilizes a wrap style removable hip belt. It is threaded through a wide belt loop sewn to the lower portion of the pack front.

Stays can be used and helpful in this configuration but careful design and planning are required to avoid conflicts between the “belt loop” and the “stay sleeves”.

On the above pack there are no stays. It is packed using the “burrito” method of stuffing the space inside of a rolled sleeping pad with the rest of my gear.

Wing style hip belts IMHO do add stress to the pack seams. That being said, the last pack that I made had the wing style belt with a plastic frame sheet and tubular aluminum stay.

Today I’ll add a “term” to the English language. The term is “Newtonism”.

Newtonism follows below.

“In an attempt to relieve my boredom I surprised myself and made something new and different.” ;-)

Party On,

Newton

I have a hard time understanding the popularity of wing-style hipbelts on larger packs. Unless such a pack is packed quite loosely and is thus very flexible, one ends up with gaps where the belt doesn't contact the hips (at 830 and 630, assuming the navel is noon). In my experience the fit associated with these gaps often leads to chaffing and poor carry.

A wrap belt with the wings anchored 4-5" apart seems to do the trick for most folks, provided there's some sort of the strap tying the bottom corners of the pack to the belt to promote stability. For me the 2011 Golite belts are an almost perfect verions of this.

If the wings are attached to be pack far apart your hip are allowed very little up and down sway movement without making the whole pack sway. This will particularly be a problem for women because they walk funny ( in a way I appreciate!) I think men walk more easily if they are not restricted by their pack too. you might perhaps look at Aarnpacks.com for very flexible hip belt systems. I prefer a wrap system although as Dave says a golite pinnacle with the wings connected 5" apart works for me too.
Either way if you have stays in the back pack they must attach to the hip belt. My adapted pinnacle has a ULA inverted U light frame with the ends of the U brought together to 5" so the load transfer is directed to the central patch.
The original ULA circuit had a wrap belt only attached with 4" velcro and the inverted U was too wide to transfer load to the attachment so the pack collapsed under moderate load. A poor design that could have been improved easily.

Very interesting. I've never had an issue with wings and range of motion. As for weight transfer, I use very tall wings (maybe six inches), and given the burrito style suspension, the wings are directly connected to frame. A wrap belt with a broad contact sleeve would probably give even better weight transfer.

Regarding stays, I'm gathering from the comments that the best approach is that stays are placed within the contact point for the wrap belt. Still unclear how that avoids the stay hitting my back, but I'm thinking it through.

Interesting you mentioned the original Circuit. I own that pack, and I don't think it carries better than my MYOG burrito style packs.

When I said original I was talking about the pack the inverted U frame came from, to transfer to my adapted pinnacle. I do not know if it is an original circuit, I doubt it.
The ULA inverted U frame at just over an ounce is a wonderful frame if applied correctly. I can carry 70 pounds without frame collapse in my pack.

I do think full wrap is better than wing-style. The most comfortable of all the packs I've made over the years has a full-wrap hipbelt that is attached by way of two straps at the bottom about six inches apart, sewn directly to the bottom ends of the sleeves that hold the stays, and one strap at the top center. It's a very direct connection to the stays, and yet has considerable flexibility. However, I don't do it that way on my more recent and lighter packs, as that connection involves more material and thus is heavier than what I do now. Now I make a full wrap belt, and sew it to the pack body with a trapezoid of stitching so that the top (the narrower part) of the trapezoid is the same width as the outside of the two stays – about 6". I figured out that for my body, that is just about the maximum width I can have and not have any gaps between my back and the belt. I find this works really well up into the 30's. Above that is where I can tell the difference between my current system and the older pack.

My stays are in sleeves that are sewn to the pack body and then the belt is sewn to that same point on the other side of the fabric, so I get a good solid connection of the belt to the stay bottoms.

Same experience as Derek with more comfort with full belts.

However, have also experienced more comfort with the Warmlite 'jackpack' design with belts that are attached at only three points: the rear center just behind the small of the back, and to the front points of rigid hinged and curved sidearms that are located at about the same position as the 'wing' belts. You can google the jackpack to see what they looked like. They should not be confused with the Jansport and other sidearm packs that put the center of pack gravity way too much to the rear. With the jackpack design, the weight falls on each side of the back, right over the hip bones.

The sides of the belt rotate up and down with hip movement while walking. I added to this some small pulleys with a block and tackle-like arrangement that keep the sidearms sufficiently closed to snug the hipbelt to the hips without requiring any buckle closure at the front. This worked well for several packs. Folks often asked about the absence of a buckle in front. Tried a regular wrap belt for a while more recently, but am going back to the modified jackpack belt that was much more comfortable.

Hope to post the next pack using one this winter. The challenge is building the hinged sidearms and frame that are really light weight.

I like a full wrap belt, but if the pack is narrow enough (11") or less, and depending on the size of your waist or hips, you can achieve a wrap around affect with side wing belts. One trick that McHale uses for the lower placement of their stays, is that they are located further outboard from the lumbar pad, at a point where many packs would place the hip-belt load lifter buckles. McHale places straps and buckles at this point as well, but are meant to be pre-adjusted for fit and not adjusted while wearing the pack, or while on the go.

Samuel,

Here’s one photo of the jackpack (scroll down to see it).

pack

Is this the type of belt you are describing?

Where would to pulleys and block and tackle be placed to eliminate the front buckle?

Daryl

Daryl,
The small pulleys, made for 5/8" webbing, are behind the hipbelt, about 9-10" apart, and are anchored to vertical carbon struts in the pack frame. The webbing straps run back and forth, a la block-and-tackle (like a 'come along')from the pulleys to the sidearms, at a point on the sidearms that is close enough to the pack frame that the hipbelt will not rub on the straps. Although that does not provide much leverage to pull the sidearms together, the block-and-tackle arrangement exerts more than enough force to keep the belt pulled tightly around the hips. The sidearms must be long enough that their front points are sufficiently forward of the hips to not rub against the hips.

After running back and forth, the webbing runs through a pulley in sidearm, and runs along the outside of the sidearm to a buckle, so you can tighten the sidearms just by pulling forward on webbing running from the buckle on each side of you. It can be done while walking.

It's quite late here now, but over the weekend, I will try to take and post a few clear photos of the belt area of one of my packs so you can see exactly how they are set up.
Thank you for your interest.

P.S. That photo is of one of Jack's earlier prototypes, much cruder than the later models that had the sidearm tubes much closer together and a much narrower hipbelt, in two pieces with one end of each piece anchored to the center of the pack frame with fabric. That allowed the belt to rotate freely, resting on the crests of the hipbones at an angle. I have found that either one or two piece hipbelts will work, so long as they are set up to rotate enough around the attachment point at the small of the back. The slimmer sidearms work better because there is less chance of them rubbing against the rib cage or the lower hips. They are a little more prone to breakage than the large radius ones shown in that photo, but with reasonable care, that is not a problem. They can be kept closed up against the pack when it's not on your back.

This is a wealth of information, guys. Thanks. My packs are usually 10 to 11 in width. Maybe this is why the wing belt has always worked for me. That said, I'm working on a full wrap belt, and the question is where to attach it.

I currently plan to place the stays about 9 inches apart, on either side of the belt sleeve. The belt will be anchored with some thick velcro patches at the edges and center of the sleeve, and covered there with a lumbar pad. I'm working from photos on the Mchale site, which can be tricky to reverse engineer. The stays will be flat McHale style, 6061 aluminum, and will run up to the center of the shoulder pad attachment point, so there is a direct line between the shoulders and belt.

The bottom corners of the pack will have a strap to pull the pack in snug.

I still plan to use the rolled pad structure as well.

Anybody see any glaring flaws in this plan?

Samuel,

Thanks for the info.

Daryl

Daryl,
Here are some images of a modified jackpack hipbelt.
First, a view of the entire backpanel for reference:

Next, a couple closer shots of the sidearms in open position:

Finally, with the hipbelt pinned back to provide a better look behind it:

This pack was built for rugged use on long treks in the 50 lb. range, was very comfortable and served well; but at allmost 6 lbs., it was too heavy for BPL. It is the 5/8" diameter aluminum tube in the hourglass frame, top shelf, and side arms that is the culprit. So I'm trying to come up with one using carbon rod, fiberglass tent pole tube and aluminum tent pole tube. The sidearms, top shelf and two bottom horizontal crossbars have to be curved, so they will be made of Easton 90 degree curved elbows for the shelf, and SMC aluminum tent tube for the crossbars and sidearms, about the same weight but a little lower diameter than the Easton .340" o.d. tent tube (They fit kite fittings better than the Easton). Lots of reinforcement with kite fittings, mostly T's, for these lightweight materials. Wish me luck.

Very clever.

I really like what you are trying to achieve with a hipbelt that carries the load but flexes independently of the bag. I have a simpler concept for a floating hip belt which I plan to build in the next couple of weeks. If it isn't a complete flop I'll post details.

A couple of days ago I came across this article on a UK site about a new Berghaus system which may be of interest. http://www.outdoorsmagic.com/gear-features/testing-the-new-berghaus-bioflex-2-pack-system/8772.html Berghaus claim a considerable reduction in energy use when using their new system. Also, being an old bloke I remember in the early 80's a TNF framed pack that had the hip belt attached to the frame through a flexible plastic fitting, so the concept has been around for a while.

I have a couple of Aarn packs. It is not so much that they have flexible hip belts but that Aarn approaches from a different direction. The shoulder straps wrap under the pack in a continuous loop sliding in a sleeve at the bottom of the pack. This provides wonderful comfort and flexibility. Add the front pockets and it is truly a different type of pack.

Mark,

I went to the bioflex link you included. The snake shaped wire within the waist belt looks interesting. Looks like it would help maintain the shape of the waistbelt.

Daryl