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Benjamin Smith
(bugbomb) - F - M

Locale: South Texas
Pack strap construction - question for the gurus on 11/13/2005 17:34:02 MST Print View

Gentle(wo)men,

I'm making a couple of ultralight ~2500 ci packs for my wife and for myself. What do you use for strap padding material? I think I'd need 1/4 inch or maybe even less - just something to keep the strap from curling and to keep the load evenly distributed across the shoulder. I've used Reflectix bubble wrap, but don't like the aesthetics of seeing it peeking out through the mesh/silnylon ;). And the walmart pads that are readily available are too fat for my application. I'm eager to hear what you guys have found. Has anyone tried cutting up a Thinlight pad from Gossamer Gear?

http://www.gossamergear.com/cgi-bin/gossamergear/thinlight.html

The 1/8 thickness might be nice - you could use two layers, and build a contour into the strap... hmmm. Anyways, I'm eager to hear what you whizzes come up with.

Ben Smith

Jim Colten
(jcolten) - M

Locale: MN
Re: Pack strap construction - question for the gurus on 11/13/2005 20:30:04 MST Print View

Gossamer Gear's make your own G4 instructions point you to Quest Outfitters for materials. They sell a wide variety of stuff including foam for shoulder straps and hip belts.

Thru-Hiker sells pre made straps

Edited by jcolten on 11/13/2005 20:34:15 MST.

Ryan Faulkner
(ryanf) - F

Locale: Mid atlantic, No. Cal
Re: Re: Pack strap construction - question for the gurus on 11/13/2005 20:35:18 MST Print View

you can buy pre made pack straps from thru-hiker.com

Shoulder Straps

Benjamin Smith
(bugbomb) - F - M

Locale: South Texas
Thanks on 11/14/2005 19:58:48 MST Print View

Guys,

Thanks for the responses - I think I'm just going to try and track down some 1/4 inch closed cell foam. I had seen the straps from thru-hiker, but since I've made a tarp and several packs out of about $10 worth of materials, I hate to drop even $10 on just straps (though that's a really great deal - kudos to AYCE over at thru-hiker.com)! Call me Xtreme-Super-Uber-Cheapo.

Anyone else have triumphs of frugality to share? I really like the pool-floatie pillow idea...

BTW - sorry about the double-post. I have no idea how that happened - I didn't refresh, I don't think I clicked twice... *sheepish* If a mod happens to see this, feel free to delete the empty post.

Ben

Edited by bugbomb on 11/14/2005 19:59:40 MST.

Ryan Faulkner
(ryanf) - F

Locale: Mid atlantic, No. Cal
Re: Thanks on 11/15/2005 13:10:14 MST Print View

if you are trying to go sub $10 I guess you arent willing to dish out the $23 for a G4 pack from Quest outfitters :-)>

but I think this may be your best solution

Benjamin Smith
(bugbomb) - F - M

Locale: South Texas
good suggestion on 11/15/2005 16:16:16 MST Print View

Ryan - lol, yeah, I'm a broke college student.... but I could certainly afford the $23 for a G4 kit. I already have a G4, and I'm looking for something a bit smaller (I hardly use half the capacity on short trips). Plus, the cheapness is part of the fun of this project.

Ben

Ryan Faulkner
(ryanf) - F

Locale: Mid atlantic, No. Cal
more suggestions on 11/15/2005 16:23:09 MST Print View

check out the LAB pack at thru-hiker.com depending on what materials you use you may be able to make a $10 pack

Rodney Liwanag's LAB Pack

or you could design your own. it dose not need to be fancy.

check out the simple design Bill Fornshell used for his pack. Bill Fornshells Pack (scroll down a little) (after that scroll down some more, and BTW you dont need the frame)

You have probably seen the Gossamer gear G6 , design something after that

There are more ideas at Backpacking.net

Hope you got all that :-)>

Edited by ryanf on 11/15/2005 17:09:04 MST.

Vick Hines
(vickrhines) - F

Locale: Central Texas
Re: Pack strap construction - question for the gurus on 11/16/2005 18:04:57 MST Print View

Ben,
RE: What do you use for strap padding material?

Automobile upholstery shops generally have thin closed cell foam. Quality varies, but I've gotten good goods there - including the 3/16 inch, sorta stiff stuff I use for shoulder straps. The Thinlight pad from Gossamer isn't very stiff - tends to fold and bunch in the strap. It helps to sew it into the side seams, then stitch over it.

If you want to cut weight and cost even more, try parachute cord adjusted with prussic knots instead of webbing with tablar buckles for your strap adjustment. Properly tied prussic knots hold, then slide as you want. An ultralight pack doesn't need anything more.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Pack strap construction - question for the gurus on 11/17/2005 03:10:09 MST Print View

> What do you use for strap padding material?

Nothing. Nothing at all.
I use a slightly stiff Dimension Polyant fabric as a single layer shoulder strap. Correctly shaped, this has worked up to 20 kg load. No foam, no padding.

paul johnson
(pj) - F

Locale: LazyBoy in my Den - miss the forest
Re: Re: Pack strap construction - question for the gurus on 11/17/2005 03:56:43 MST Print View

Mr. Caffin,

for the area in contact with the body, how wide is each strap?

Vick Hines
(vickrhines) - F

Locale: Central Texas
Re: Dimension Polyant pack straps on 11/17/2005 08:50:41 MST Print View

Roger C:
Dimension Polyant. What is it, where do you get it, how do you use it? Does it roll or wrinkle?

Benjamin Smith
(bugbomb) - F - M

Locale: South Texas
more ideas - great! on 11/17/2005 10:06:45 MST Print View

Ryan,

I've spent an embarrassing amount of time looking at all of Bill's creations. I've been lurking on this board for about 6 months now - finally registered, and followed his threads over at whiteblaze and backpacking.net as well. I've checked out Rodney's packs, even considered having him make one for me, but what the heck - this is more fun. And, yes, my finished product should look very similar to the G6.

I already have the main pack body ready to go - I'm really just looking at strap ideas, and strap attachment methods. I think that I can have a slightly padded shoulder strap - Vick, the auto foam you referred to sounds perfect, so I'll check local shops - and still come in with a pack that weighs 6-7 ounces or less. Those of you who have made packs, or who have attached straps to packs before, did you just bar-tack them on? Obviously, for light loads, that's more than enough reinforcement, but while I'm at it, I thought I'd come up with an integrated, slick-looking attachment method. I think I may try and have the straps attach to the inside of the back of the main pack bag - I'd leave the back panel a little lower than the other side panels, then I could attach another piece on top of it to bring the back up even with the sides and front. The extension collar could then be attached to this now-level area. Anyways, I'll post pics once I get some more time to work on this.

Roger - I second the motion - I'd love to have more details on the material you referred to. So far, it sounds like you really have some unique ideas, and my interest is piqued.

Ben

Edited by bugbomb on 11/17/2005 10:07:19 MST.

Mark Larson
(mlarson) - MLife

Locale: Southeast USA
Re: more ideas - great! on 11/17/2005 10:26:45 MST Print View

Dimension-Polyant is a company that makes a pretty big variety of different sailing fabrics. I'm also curious about which specific fabric you put to use, Roger. Also, their website has some good photos and marketing, but doesn't seem to have an small-time ordering part--any suggestions for retailers you've had good dealings with?

FWIW, GoLite now uses the D-P "X-Pac" fabric on their Unlimited series of packs. It is pretty beefy feeling, but not too heavy.
-Mark

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Dim Poly shoulder straps on 11/17/2005 14:37:33 MST Print View

I am using VX42 fabric, 60 mm wide, for the straps. You can see the straps in the scond pic at http://www.bushwalking.org.au/FAQ/DIY_RNCPacks.htm
But there is a whole range of this multi-layer fabric.

I got the fabric as a sample from Dim Poly themselves. I believe they have started a small order channel themselves. Ask them. They want to get into the outdoors gear market.

paul johnson
(pj) - F

Locale: LazyBoy in my Den - miss the forest
Re: Dim Poly shoulder straps on 11/17/2005 14:48:18 MST Print View

Mr. Caffin,

many thanks for the reply. nice looking pack. 60mm - wide, but not too wide. noticed the hip-belt. my guess, i could be wrong, is that's why you can get away with no padding in the shoulder straps (coupled with the 60mm width). would you have padded the shoulder straps if you weren't using a hip belt?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Dim Poly shoulder straps on 11/17/2005 15:01:38 MST Print View

> noticed the hip-belt. my guess, i could be wrong, is that's why you can get away with no padding

No, the hip belt is ONLY used to prevent side-sway. I can travel with it loose or even undone.
The straight web back with the curved frame is the secret. This puts the load on my back; the shoulder straps take some load and keep the rest on my back.

Well, having a light pack helps of course!

paul johnson
(pj) - F

Locale: LazyBoy in my Den - miss the forest
Re: Re: Re: Dim Poly shoulder straps on 11/17/2005 15:10:08 MST Print View

>>"The straight web back with the curved frame is the secret."

very clever. thanks for explaining.

Vick Hines
(vickrhines) - F

Locale: Central Texas
Attaching shoulder straps on 11/19/2005 14:28:00 MST Print View

Ben Smith:
When the pack bag is of lightweight fabric, you need to distribute the area of contact with the straps.

I use Velcro patches on experimental packs and packs meant for wide load variations (thruhiking) so I can adjust torso height. Two patches of four-inch-wide loop Velcro, 9 inches long go on the bag and 6 inch long X 4" strips of hook go on the shoulder straps - if the straps are separate and not joined at a 'Y'. If joined, a single 4"wide patch will do. Four by 6" Velcro will hold lots more than an ultralighter will ever carry. For packs hauling up to 36 pounds, I use two rows of bar tacking to hold the strap to the Velcro. Never had a failure. But don't use narrower Velcro. For some reason, 2" passes some threshold and just hasn't worked for me. Velcro is light.

If you are sure about where the straps are to go, a secure method is to stitch the strap(s) to a separate reinforcing patch or panel that extends one inch above and 4 inches below the point at which the strap is attached. The patch can be as wide as you like, but at least an inch wider than the shoulder strap attachment width. The stitching can go through patch and pack body or just through the patch, but in the latter case, you have to use a heavier fabric. The upside is it is easier to water seal when the bar tacking does not go through the pack body.

A good bar tack is OK for the highest stress point, where the strap actually intersects the back of the pack. That point gets focused stress when you pick the pack up and swing it on. But an extra line below that bar tack line will help carry the steady load during hiking. It is not concentrated stress you are reinforcing against here, but the more-or-less steady pull when the straps and pack are sweat soaked, hot and being tugged. Those are fabric-hostile conditions that will tear the straps off if they are not broadly reinforced. If your reinforcement panel is stitched uniformly and securely to the pack body, you will need no further reinforcement. Give some thought to the reinforcing panel. For packs carrying up to 25 pounds, I have used 1.8 oz, silpreg with no problem. 4 oz. Oxford works OK for heavier packs. Heavier than that is not necessary. As mentioned, the reinforcement does not have to be large.

Benjamin Smith
(bugbomb) - F - M

Locale: South Texas
Re: Attaching shoulder straps on 11/21/2005 17:55:04 MST Print View

Vick,

Excellent suggestions - thank you very much. Just so I understand your first paragraph - you use velcro to attach the pack strap to the pack body? Your writing is perfectly clear, I have simply never heard of or thought of that before. It certainly would give a great degree of flexibility. If I try this method, I'll certainly keep in mind your recommendations on the appropriate width to use.

As far as your second method - I agree, that's the way I've done it before (bar tacking to a reinforcement patch) - I'm really just trying to come up with a way to attach the straps to where I don't have to mask an external attachment. The backpack I take to school has the shoulder straps sewed into a seam, and it has carried easily 30 lbs of books for about four years now without showing the slightest sign of weakness at that point. You have obviously given this a lot of thought - have you ever tried attaching the straps at an existing seam, both for reinforcement and for aesthetics (obviously one of these is more important than the other...)?

Ben

Vick Hines
(vickrhines) - F

Locale: Central Texas
Re: Re: Attaching shoulder straps on 11/21/2005 18:50:35 MST Print View

Ben,
Surprising that Velcro will work to make adjustable shoulder straps. Can't imagine why it is so rarely used. The only tricks are to use 4" wide stuff and to bar tack the strap 1" below the top of the Velcro patch to which it is sewn. That creates one of the release-resistant configurations for Velcro.

One line of bar tacking is enough because the Velcro takes up the stress when you haul on the strap.

Another important trick is to spank the Velcro when you mount the straps. That *sets* the Velcro. Don't be alarmed if if makes a farty sound now and then under stress (such as jerking the pack up with one strap). It's just protesting, not breaking loose. After it 'sets' it will stop that.

As to second question: using an existing seam. Sure, you can do that, but I would put that seam on top of a reinforcement patch extending at least an inch higher on the pack back. I would also do at least an 'X-box'of stitching below the bar tack and through the covering fabric and the straps. That would give you the combination of strength and aesthetics you want.

Think of it like this. I'll bet your school pack is not 1.3 ounce ripstop. More likely 10 oz. Cordura (or more) sewn with Nylon 66 upholstery thread. You probably could pick up a car with those straps. As usual, commercially produced stuff is overkill. Lightweight fabrics take a little more care. If you do it right, you can pass your new pack on to your grandkids. Afterall, silicone never goes bad - unlike the polyurethane on your school bag. With reasonable care, Nylon is good for decades.

Edited by vickrhines on 11/21/2005 18:54:58 MST.