Stretchy material longevity

[outdoor_matt]

Hi guys,
Just curious about people's experiences with the stretchy material used on the Exo packs, Kifaru side pockets, etc. I'm sure it's fairly durable, but for those with experience, does the material tend to loose a lot of it's "stretchy properties" over time? Like the shape charge looks like an awesome pack, but in my opinion the stretchy side pockets are what limits it's effective life span. Wouldn't a good replaceable shock cord (like on the Seek outside pockets) be a better long term solution, or am I just overthinking this?

Looking for thoughts
Matt

 

[Bender]

Afternoon Matt,

I put 1" mil. grade elastic at the top of the Shape Charge bottle pockets to reinforce that pocket and keep them pulled in to retain what's in there. The 1" elastic keeps the fabric from expanding to the point where it would break the fibers and likewise the fabric keeps the elastic from doing the same. The problem with rubber based elastics only really arise when they over extend and rip the rubber, especially in cold temps. The fabric may develop problems if it is really over loaded and stretches out the fibers but for that reason, the Shape charge bottle pockets (and most all of the outer pockets that use the 4 way stretch Tweave fabric on our packs) are double layered. I'm pretty good at destroying stuff so I work redundancies in when it isn't too much of a weight penalty.

I've made pocket systems with replaceable bungie cords and it adds a lot of complexity to the pocket. The anchors and opening have to be accessible and the anchors are usually located near seams which can cause problems during sewing. The more potential problems with complex solutions near seams usually mean repairs or seconds in the end. Easier to build them so they wont break. I will say that sewn in bungie cord is a bad idea if not done right. It doesn't take to sewing and will pull out of the seam. Flat elastics are made to be there however. Hit me up if you have any more technical questions. [email protected]

 

[Tradchef]

I’ve always wondered this as well. I tend to shy away from packs with that.

 

[Mt Al]

This is a generalized statement as not all elastic materials are equal, nor are all manufacturers of packs equal in how the select, contain and package elastics. Also, there's way more out there than I know, but here goes:

Elastic-type material can degrade and lose it's elasto-mojo if left in the sun for long periods or if it's stretched out and left stretched out for a long time. UV inhibitors can be put into the elastic material but that can limit the qualities.

The design packaging that Bender/Kifaru lists above eliminates a TON of any issues with elastics in pockets. Contain the elastic within fabric covers or tubes, measure and make patterns so the elastic stops stretching before it reaches its limit, etc.. The buyer just has to be careful and empty the pockets after a trip. Cutting and heat sealing elastic used to be a challenge, like the rubber/elastic catching on fire, smoking like a house-a-fire, etc.. I don't think that's an issue anymore.

I like elastic side pockets vs. zippers, just me.

 

[outdoor_matt]

Afternoon Matt,

I put 1" mil. grade elastic at the top of the Shape Charge bottle pockets to reinforce that pocket and keep them pulled in to retain what's in there. The 1" elastic keeps the fabric from expanding to the point where it would break the fibers and likewise the fabric keeps the elastic from doing the same. The problem with rubber based elastics only really arise when they over extend and rip the rubber, especially in cold temps. The fabric may develop problems if it is really over loaded and stretches out the fibers but for that reason, the Shape charge bottle pockets (and most all of the outer pockets that use the 4 way stretch Tweave fabric on our packs) are double layered. I'm pretty good at destroying stuff so I work redundancies in when it isn't too much of a weight penalty.

I've made pocket systems with replaceable bungie cords and it adds a lot of complexity to the pocket. The anchors and opening have to be accessible and the anchors are usually located near seams which can cause problems during sewing. The more potential problems with complex solutions near seams usually mean repairs or seconds in the end. Easier to build them so they wont break. I will say that sewn in bungie cord is a bad idea if not done right. It doesn't take to sewing and will pull out of the seam. Flat elastics are made to be there however. Hit me up if you have any more technical questions. [email protected]

Awesome, thanks for the detailed response, Bender. That certainly answers a lot of my concerns. I know Kifaru makes long-lasting products, so I figured stretchy material can't be all that bad if you guys are using it.

 

[outdoor_matt]

This is a generalized statement as not all elastic materials are equal, nor are all manufacturers of packs equal in how the select, contain and package elastics. Also, there's way more out there than I know, but here goes:

Elastic-type material can degrade and lose it's elasto-mojo if left in the sun for long periods or if it's stretched out and left stretched out for a long time. UV inhibitors can be put into the elastic material but that can limit the qualities.

The design packaging that Bender/Kifaru lists above eliminates a TON of any issues with elastics in pockets. Contain the elastic within fabric covers or tubes, measure and make patterns so the elastic stops stretching before it reaches its limit, etc.. The buyer just has to be careful and empty the pockets after a trip. Cutting and heat sealing elastic used to be a challenge, like the rubber/elastic catching on fire, smoking like a house-a-fire, etc.. I don't think that's an issue anymore.

I like elastic side pockets vs. zippers, just me.

Super, thanks for the info and tips on preserving elastic longevity. I'm sure, like most anything, if the material is taken care of and not abused beyond what it's designed to do, there should be no long term problems with it.