Feb 4, 2012 at 1:02 pm #1285173
I've been cooking this one for a while and came across a couple old Jansport external frame packs to fiddle with. I've always wondered what a bare Jansport frame weighs and here's what I found:
Full size Rainer style frame: 1 pound 9oz
Rainier style frame with upper pack loop removed: 1 pound 6oz
Smaller Scout style frame 1 pound 4oz (this was a surprise– I expected less)
I took the straps, belt and back pad off the Rainier frame and put it on the Scout frame. I wanted to save top hamper as well as weight. Another surprise is that both frames are the same width. I cut the castings for the upper pack loop off and it weights 2 pounds 8 ounces as shown in the photos.
The whole idea is to have a frame that I can attach large silnylon stuff sacks and equipment.
I have a fairly light frame with decent straps and belt and I have several cross bars to work with. The simple solution seems to be to just strap stuff sacks onto the horizontal bars. Does anyone have alternate methods to attach bags to a frame like this?Feb 4, 2012 at 1:22 pm #1834432
@maynard76Locale: New England
So the frame weight is just the metal frame without any padding or straps?
That seems unbelievably light.
Maybe you can add lighter belt/strap from Granite gear or even SMD to get it even lighter.
As for strapping things on, maybe something the the ULA Epic? Lots of possibilities.
Have you thought about cutting the top off to shorten it? or do you want the capacity?Feb 4, 2012 at 1:55 pm #1834445
"So the frame weight is just the metal frame without any padding or straps?
That seems unbelievably light."
I typoed the weights— that is pounds and ounces. Jansport was (still is) turning out very light packs considering the capacity and load capabilities. That frame is very thin, high quality aluminum tubing. IMHO, if Jansport applied UL techniques to their pack bags and harness, they would have some very light packs for their capacity. For those carrying stuff like photographic equipment and other heavy or bulky stuff, these external frame packs are great. Fantastic for bear cans.
"Maybe you can add lighter belt/strap from Granite gear or even SMD to get it even lighter.
As for strapping things on, maybe something the the ULA Epic? Lots of possibilities."
Indeed. I don't sew (yet) and I'll be looking for alternatives, but for the time being, the Jansport waist belt is comfy.
"Have you thought about cutting the top off to shorten it? or do you want the capacity?"
I did think about that, but that was the idea of using the Scout frame. The Scout is about 32" tall and the Rainier is more like 39" and that extra 7" is mostly top stuff— flying high to catch on branches and crawling under blowdowns, not to mention the center of gravity. I wanted the cross bar for possible attachment (perfect place for a sleeping pad) and I am concerned about the strength. The bar that mounts the shoulder straps is fully adjustable and I think the frame would rack if the top bar is removed. As it is, that section of frame doesn't weigh much– about 3.5oz comparing the weight of the top loop off the Rainier.Feb 4, 2012 at 2:17 pm #1834458
Do you still have your Outdoor Research Dry Peak bagger? Lashing one or two of them to the frame using their straps might give you an idea of how the frame handles. That or any of your other packs? And then you can always copy Luxury Lite stuff.Feb 4, 2012 at 2:54 pm #1834490
"Do you still have your Outdoor Research Dry Peak bagger?"
I don't, but that is a good idea. I do have some roll-top stuff sacks. I was thinking of something really light, like a silnylon pack liner, or Sea to Summit roll-top silnylon bags. I could use knotless net and zip ties and throw silnylon stuff sacks inside. I have one of those terrible net hammocks that could be adapted very quickly. With the net, I could just use a trash compactor bag inside to keep it all dry. The wet stuff would have lots of ventilation stored between the net and the trash bag. If I carry a few spare zip ties, I could alter the pack capacity and shape as needed.Feb 4, 2012 at 3:09 pm #1834497
That is cool Dale, I just came across a free Kelty Tioga Frame. I haven't weighed it or played with it yet but was thinking it could be a lightish load hauler for a long walk/ski in to a base camp where I want to set up my Tipi. I have been doing alot of reading on therapeutic adventure lately and in a section on the intentional use of limited equiptment they spoke of a program having their clients wrapping there gear in tarps and lashing it on the frame like they would back in the day. Depending on the conditions you are hiking in(ie bushwacking probably not) a sil tarp could be dual use for this. Depending on weight I was also thinking it would be cool to use webbing and fastex buckles to set up a load carrying trampoline type system.Feb 4, 2012 at 3:12 pm #1834498
I have had good experiences with the Granite Gear eVent compressor dry bags especially for my down bag. You might be able to really play with balancing the load . And the Net sounds great . I've been thinking about using one of those cheap Coghlan's net Laundry bags for wet stuff. I hope you post how this works out as I have 2 external frames and one is a very light Alpenlite plastic frame to play with.Feb 4, 2012 at 3:17 pm #1834501
"…I have 2 external frames and one is a very light Alpenlite plastic frame to play with."
I have looked at the old Coleman Peak 1 plastic frames and they have their appeal. They have many lashing points and look easy to adapt. I would want more modern straps and waist belt.Feb 4, 2012 at 3:23 pm #1834504
Gerry wrote, "…wrapping there gear in tarps and lashing it on the frame. Depending on the conditions you are hiking in(ie bushwacking probably not) a sil tarp could be dual use for this"
Great idea. One impetus for this rig is when using my hammock setup, which robs volume. I could use the hammock tarp to wrap it all up and lash it on. A small stuff sack added to the mix could handle stuff to use on the trail, like snacks and rain gear. That would avoid opening the tarp to get stuff out. I need some water bottle pockets too.Feb 4, 2012 at 3:28 pm #1834505
I agree 100% on that suggestion. I can get something at least decent at Goodwill most likely or on ebay.I'd like to go more modern and have hipbelt pockets as well. My other external frame is expedition grade with a great hipbelt and it even stands up by itself.Feb 4, 2012 at 3:39 pm #1834509
Miguel ArboledaBPL Member
@butukiLocale: Kanto Plain, Japan
All these years I've kept the frame of my old Longbed External Frame Pack, always thinking that perhaps someday it might still be useful. After seeing this thread today I weighed the frame, stripped of all extras. It came to 820 g (1.8 lb). Have to see what I can do with it.Feb 4, 2012 at 4:06 pm #1834522
Daryl and DarylBPL Member
@lyrad1Locale: Pacific Northwest, USA, Earth
This is exactly how I started with my pack modification project, about 12 years ago.
Dale sounds like Daryl and we are both from the Pacific Northwest. Related?
My sequence went something like this:
(1) Eliminate as much of the frame as possible.
(2) Eliminate the bag and lash things to the frame.
(3) Replace bag with myog bag.
(4) Replace frame with myog aluminum frame.
(5) Replace aluminum frame with myog carbon fiber frame.
(6) Replace waist belt with myog belt.
(7) Replace shoulder straps with myog front bag.
I think you are going to enjoy this.
DarylFeb 4, 2012 at 4:37 pm #1834537
Paul McLaughlinBPL Member
I'm not surprised at the weight of the frame. I have an old Trailwise external frame, which I got around 1972 or 3 and made my own packbag for. Later, around 1982 or so, I cut the frame down somewhat and made a new bag and new harness. It weighs 3lbs 10 oz, with a HUGE bag on it that is made of 4 oz oxford. I haven't weighed the bag and frame separately, but I would guess the frame and harness are about the same or a little lighter than your Jansport.
Interestingly, I originally wanted a Jansport frame back in 72, and wrote them asking if I could buy a frame without bag – they said no. I liked the adjustability and the flexibility of the frame compared to welded frames.Feb 5, 2012 at 4:48 am #1834720
David GoodyearBPL Member
This is a very do-able project. I did something similar last year.
The cool thing about the externals is that you can easily make interchangeable packbags for different hiking situations.
Granite gear (flatbed) and mystery ranch (crew cab) have some cool designs for easily lashing on a load and can be made significantly lighter by MYOG. You could make a cradle out of straps and a little pack cloth – attaching the straps at the side pins and looping around the top and bottom. An easy way is to just add a grommet that lines up with the frame pin holes.
DaveFeb 5, 2012 at 10:31 am #1834824
@socal-nomadLocale: North San Diego county
Mystery Ranch crew cab frame is awesome I have seen videos of the Reps carrying around people at the SHOT show with a 160lb man hanging off the back. I own 3 mystery ranch packs the street fighter,Sweatpea, Big sky.
The street fighter and sweet pea the have just a futura frame it only the HDPE frame sheet in combination with Mystery ranch composite Yoke system used on all the packs,the yoke system is the key to all mystery ranch packs load carrying capability. The big sky has the futura frame with fiberglass X rod frame.
What really surprises me is some one has not come up with a all Titanium small tube welded external frame with a shelf on the bottom. It would solve the weight problem and would carry a lot be pretty much indestructible for the UL frame packers.
TerryFeb 5, 2012 at 2:23 pm #1834901
"What really surprises me is some one has not come up with a all Titanium small tube welded external frame with a self on the bottom"
Exactly. Good sideline for a bike frame shop that does Ti. There's one close to me— I'll have to stop by and chat :)
Next stop would be a line of Cuben stuff sacks with some sort of attachments for the Ti frame.Feb 6, 2012 at 7:38 am #1835173
@flriderLocale: The Southeast
It might be what you're looking for, though it isn't the lightest option. It doesn't require anything but bar tacks and straight stitching, since you've got a set of shoulder straps and a waist belt already attached to the frame. It's really easy to do, once you get the timing of the sewing down.
Looking at the way that frame is designed, the simplest way I can see for putting things together would be to make a PALS array out of a doubled-over layer of nylon, draped over the top bar on the frame (sew the webbing to one side of the nylon before draping it), with four "keeper" loops (either webbing or grosgrain with velcro, side release buckles, or just sewn together if you don't want them removable), two over the middle crossbar and two over the lower crossbar, all bartacked to the side of the array facing your body (again, before actually putting the array on the frame). That should keep it from moving around when you're hiking, but you might wind up wanting to add a couple more loops to attach the array to the vertical frame supports.
It won't be SUL, but it should be really easy to use.Jul 3, 2014 at 8:18 pm #2117263
Paul FrenchBPL Member
@ssghawkLocale: Northern Texas
I happen to have an older model jansport frame that I believe was for a child. I removed the upper curved bar and I believe there will not be any significant warping. The shoulder strap bar was either original or modified by someone to be adjustable by an aluminum bolt, but no extra holes. There are no heavy cam lock adjustments. I did not trust the old straps and ebay has new shoulder/waist belts and bottom frame sets for stan(what?) freighter packs for $10. I am into lite but comfortable if I have to carry gallons of water(This is Texas)plus my gear. Still fooling around with the proper placement of the waist belt; probably will need to drill holes. The old mesh style back rests weigh less than the newer Jansports foam ones and are cooler. I also have various child's kelty external frames with packs between 15 and 30 liters I estimate. I bought a few waterproof (Yea right?) 20 liter super lite packs (China) and various stuff/laundry bags sized from about 10 liters up to 40"X 50".
I also have several of the old jansport external frames with the metal wings with good pads. (yes, I hoard camping equipment. LOL)I like winter camping when the snakes are frozen stiff since there are a ton of them where I go and there will not be snow or water down where I will be going.
I am interested to see how those "wings transfer the weight. Any insight or experience will be appreciated.
So when I get time, I will start playing around with the many, many alternative configurations. It should be fun and I need the treadmill with backpack time. Long term goal will undoubtedly be titanium once I figure out what I really need.
Darn this is fun.Jul 5, 2014 at 8:20 pm #2117554
Sam FarringtonBPL Member
@scfhomeLocale: Chocorua NH, USA
"That frame is very thin, high quality aluminum tubing."
Nothing wrong with mods to lighten Jansport and other packs using 5/8" OD alloy frames. Maybe the current J-sport tubes are lighter? But the tubing on the older ones runs around 1.4 oz per running foot. It is a more durable tube than highly tempered ski poles that run around 1.2 oz in 5/8" OD.
Try as I might, couldn't get around the fact that high quality alloy tube running just under 3/8" OD, like Easton .340, runs less than half the above weight, around .5 oz per running foot. The catch is that the elbows that appear to have ferrules stuck in the ends, are actually two layers of tube inside the elbow, and therefore heavier.
But that's what I'm working on this year, limiting the Easton tube with heavier elbows to the lower section of the pack that takes the most abuse, and using lighter carbon fiber and fiber glass tubing with lighter Fibraplex elbows for the upper part of the frame.
Would like to stop just gabbing about this and get something finished to post about, but its been a real slog. Some projects just take longer to mature.
It might be of interest, though, to look at a photo of the the parts laid out about a year ago, before getting into the Fibraplex elbows to save weight:
Jul 6, 2014 at 6:03 am #2117599
Jesse AndersonBPL Member
@jeepin05Locale: Land of Enchantment
Out of curiosity, what made you build your frame in an hour glass shape? The only other frame I've seen similar in shape to yours is the one used in some Kuiu packs but that's more of an X made from Carbon Fiber. It seems like with yours, you are adding some weight with the extra material length and with the extra elbows. Is there something inherently stronger about your hourglass over the traditional rectangular frame?Jul 7, 2014 at 9:18 pm #2118109
Sam FarringtonBPL Member
@scfhomeLocale: Chocorua NH, USA
AFAIK, the hour glass shape is the most efficient, in terms of the length of tubing needed to keep the pack contents away from poking into the back.
With the ladder shape, a fair number of horizontal cross tubes are needed. Doing the math, and also just making scale drawings and totaling the tube length, confirmed that the ladder frames use more tube and more fittings, so other things bring equal, are heavier.
Not that we shouldn't pack carefully to keep the contents from poking through, but when using several stacked horizontal stuff sacks for most of the gear, I've found the hour glass shape is the lightest per se for keeping stuff from protruding against the back.
The hour glass has the additional advantages of being quite strong, stronger than a ladder IMO, and working well inside an envelope that supports a suspended mesh back panel. Some say such panels move the weight too far to the rear, but when properly designed, the weight of the pack combined with the pressure of the back against the mesh panel leaves only a small gap between the contents and the back.
Bean's had a pack named AT55 that did a beautiful job of this, but was a design and materials disaster in many other respects. DAK has an hourglass or butterfly frame shown on its DAK toys site that looks ultralight, but info is scarce, inquiries are ignored, and I don't know if any company has made packs from these frames. Maybe someone here will know. Then there was the defunct Alpine Designs frame made of ABS tube that I used to build my current pack, that rides very close to the back. It's frame and mesh backpanel are not stiff like an Osprey; but rather, flex with the back. Bean's wouldn't replace the butterfly frame on the AT55, so hope to repair it with Ti stake rod, add a lumbar pad to limit slipping, and give it to a friend for fishing trips. The big outside mesh pockets will be good for that. Also added an Osprey closure on the hip belt to make it easy to cinch tight.
As for the tent tube hourglass mentioned in the earlier post, would love to be able to make an entire hourglass out of bent tent tube, but Easton 340 won't bend to the small radii; hence the elbows prebent by Easton and Fibraplex. The nylon hose barb Tees and Wyes are very light with the barb sections cut off, and the fabric will be in the 2.6-3.0 oz range, probably one of several balloon cloth remnants a rag picker has sold me. The proof of the pudding will be the actual weight when the evolving design, with less fittings and less cross tubes, is done. We'll see.
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