Jan 7, 2008 at 8:32 pm #1226628
Two mates and I are conducting an expedition in August this year in South Australia. Essentially its 12.5 days and 625km, ~50km/day. Base gear weight excluding the actual pack is ~3.25kg, food ~12kg, water peaking usually at about 5L. This means at the start, pack weights will be around 21kg.
One Planet, an Australian Manufacturer of Rucksacks and Sleeping Bags have offered to modify/make a limited run of three modified Shadow Rucksacks for our expedition.
What we have to do, preferably in the next couple of weeks, is put together a package detailing what we want, and they will work out what similar spec fabrics they already have (from samples, etc) and what price they can do them for us as a Pro-deal. They will make the packs next time they do a production run of Shadows (hopefully before August…)
Essentially, what I want to do is mostly to the pack body. The harness is near perfect for these weights and activity levels…we already have these packs and have tested them extensively. They are basically perfect for our needs, we just want to trim the weight as much as possible, whilst still maintaining enough durability for minor Australian Scrub and the weights carried.
So, for the harness…
…changing the harness length adjustment buckle for something smaller and lighter webbing (this is more ergonomic)
…adding some extra, "stiffer" foam to the lumbar pad(ergonomic thing we have found again on long days-not normally a problem).
For the body (this is where I want your input)…
…changing back panel fabric to something with reasonable strength, but alot lighter than 500denier nylon. I am thinking something appx 4oz/square yard, like oxford pack cloth. 1.3oz silnylon is possibly too weak here (One Planet will only have to reinforce it for the harness…and we may end up using this pack for other expeditions with larger pack weights more like 30+kg, so I don't want seam failures), I was thinking 2.2oz silnylon, but again, will this be strong enough? Having a heavier fabric in this zone will help with scrub durability aswell (small amount expected, cf typical Aus conditions).
…Base, I am thinking the same fabric, in one piece from the back panel. We will be careful putting this pack down, and shouldnt have to "bum" our way over obstacles.
…Side panels of 2.2oz silnylon ripstop…I am pretty confident here that 2.2oz will be tear resistant enough for this application. Has anyone tested this weight material in North American Scrub? How does it fare?
…rear panel…this is the lightest panel on the standard Shadow, at 420denier (~6oz). I reckon this should probably be 1.3oz silnylon, or perhaps 0.97 thru-hiker spinnaker (if people think this is similarly durable-I am guessing it is from the feel of a sample I have).
…Lid…design left as standard (this will make it easier on their production line), but changed to same fabric as back/base panel. The lid sometimes cops a hammering in Aus bush.
…lid strap and buckle…changed to something really small and light. I am think a 1/2 inch buckle and webbing. The current one is complete overkill (its bigger than a standard UL pack's waist belt!)
…throat gusset/extendable throat…this pack currently doesn't have one, but I am thinking it would be handy…something simple made from either 1.3 silnylon or the 0.97 spinnaker.
…Compression Straps…I want to get them to incorporate a full compression lacing system, aka GG Mariposa. This is where I really need suggestions as to placement of loops, etc, from you guys. The current compression straps are complete overkill…there are 6 of them, not including the lid strap, and none of them are traditional base compression straps!
…Bottle Holders…mesh left as standard, fabric changed to same as back/bottom panel. The compression strap will be removed as we have found its not needed to keep the bottles in.
One Planet have been quite accomodating and helpful with this. They are a small company…probably almost the equivalent of a cottage manufacturer, and they make their gear in Melbourne Aus, whilst all other Aus manufacturers have gone off-shore. Hence, they don't normally sponsor people at all. They are willing to make these packs for us at pro-deal prices. They can't go insane with changing dimensions and things (this will cost them time and money on the prodcution line), but materials is something they can do, and simple things like the compression lacing system loops shouldnt be an issue.
My aim is to get the Shadow down to about 1.1kg, rather than the current ~1.6kg for the Long harness. One Planet think that the harness, including the current back panel (at ~8oz fabric) weighs just under a kilogram, so this will be tough.
AdamJan 8, 2008 at 5:06 pm #1415357
@retropumpLocale: The Antipodes of La Coruna
Why not make things easy on One Planet and just specify Dyneema GridStop for all the pack fabric, except maybe silnylon where durability is not a big issue? This stuff is tough and light-should be perfect for your needs.Jan 8, 2008 at 5:25 pm #1415360
id make it full dyneema but the expense…and also they may not be able to source the fabrics.Jan 9, 2008 at 3:08 am #1415416
@terraLocale: Sydney, Australia.
This was my thought also whilst reading your post Adam. I have a couple of Go-lite packs here and the dyneema works well. Surely they can get some as a manufacturer, if only for testing/sample purposes.
The only problem i've had with the dyneema fabric is a tiny scuff on the daypack where the corner of a hard edged item pinched the fabric as I scrambled/slid down a rocky gully. My fault really – and you will have enough soft items to pad the pack in wear areas so this doesn't happen.
I also would go with spinfabric on the back and other non wear panels.
Instead of compression straps and buckle for the extending lid, perhaps just use a V shaped bungy over the whole lid.
Or hack the lid off altogether… ;-)
Good to hear OnePlanet are having a go to help out some ultralighters. I will give them preference in the future due to this.Jan 9, 2008 at 3:20 am #1415417
Arapiles .BPL Member
For simplicity I'd use Dimension Polyant with SilNylon on the front and lose the lid unless it's done in a really, really light fabric. The typical Aussie pack lid is usually over-engineered.Jan 9, 2008 at 1:42 pm #1415476
@retropumpLocale: The Antipodes of La Coruna
I was under the impression that Dimension Polyant is not very puncture resistant…but haven't personally tried it.
My oartner backed over my fully laden GoLite Gust with a HiLux. Despite trashing some of the contents of the pack, the pack itself was completely undamaged even though there were some sharp objects created by the impact. It has been through several years of all weather and all terrain hiking without a blemish. Nothing fragile about this fabric!Jan 9, 2008 at 7:10 pm #1415546
Franco DarioliBPL Member
I think that the minimum order for dyneema is a 700 m roll.
FrancoJan 9, 2008 at 7:38 pm #1415551
Andrew at One Planet mentioned that they have quite a range of fabric selections in small quantities available, that they have recieved in the past as samples, etc. So they may have some Dyneema; maybe enough for critical areas.
I agree with removing the lid…we dont need it, and I dont want it, but they may want to leave it on as it is part of the production process. If they make a pack I dont really want to make mods to it myself, like hacking the lid off…though I have thought about it! On the current shadow it would probably save about 200gms, especially when taking the lid strap into account.
If it works out too expensive I won't be able to afford it, and I'll either stick with my current shadow (and bear the weight), or I'll make up a 1.30z silnylon pack and transfer the harness components to it. If it only lasts this one trip thats fine by me.
As it stands the trip is going to cost each individual about AU$2k, (we are cutting ounces on everything…everything needs replacing/upgrading, and there are food, fuel, SatPhone, EPIRB costs, etc). I probably sounds like a complete stinge given the opportunity presented to me here…Jan 10, 2008 at 12:23 am #1415569
Arapiles .BPL Member
"I was under the impression that Dimension Polyant is not very puncture resistant…but haven't personally tried it."
Depends on the weight/thickness – both my Nippn sleeping bag and my MS Ghost are made of Dimension Polyant, but they're very different fabric weights – the sleeping bag fabric is more like spinnaker cloth, and I think that the R2 pack that Will got made up and reported on recently was a lighter weight than the Dimension Polyant MS Ghost uses. I know that X-Pac (which is Dimension Polyant) has been available in Australia, whereas I've never seen Dyneema here which is why I suggested it.Jan 10, 2008 at 2:17 am #1415577
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
> I was under the impression that Dimension Polyant is not very puncture resistant…but haven't personally tried it.
I have made a number of frame packs using X-Pac. The very lightest version is a bit prone to abrasion, but the heavier weights are pretty good, and versions like VX42 have a Cordura face. Very good.
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