Framesheets v.s. stays

[Eric Blumensaadt]

Why do some pack designers use framesheets instead of internal stays?

Definitions:

FRAMESHEETS> semi-rigid plastic and foam sheets used to stiffen a pack's back for light load transfer of pack weight to the hipbelt and to retain a pre-determined pack shape.

STAYS> aluminum rods, tubes or flat "bar stock or carbon fiber or engineering grade fiberglass reinforced plastic vertical pieces (or single piece) used to stiffen a pack's back for load transfer of weight to the hipbelt.

I own a large Camelbak daypack (2,800+ cu. in.plus 800 cu. in. of side pockets) that had a framesheet. I had to add 1" wide aluminum stays to the pack to get decent load transfer to the hipbelt with a fully loaded pack of day ski touring equipment.

In my experience a framesheet has very little support and ability to transfer a load much over 20 lbs. (9 kilos). So why are they used??? Can the weight savings really be that much?

[Mat Tallman]

Frame sheets are lighter, and with proper packing and compression are fully capable of transferring most of the load they're designed to support to the hips.

You'd be hard pressed to find a pack manufacturer recommend a frameless (or pack with just a frame sheet) pack for much over 20 lbs. For less than that, they're very capable with proper packing, load distribution, and compression.

Stays are also very body specific. No two spine curvatures are identical, and if the curve isn't relatively close, the comfort will be…absent, hence the importance of pack fit in an internal frame pack. Plus, if the pack isn't well designed, stays can end up jabbing the wearer in the back as foams and fabrics wear into (or out of) shape. Adding enough reinforcement to prevent this adds more weight.

Those of us who don't use frames don't typically carry loads above the range frameless packs are designed for. I didn't really think I'd ever be able to work with a pack without a frame/stays, but since I've jumped ship to frameless packs, I have no intention of going back, unless I'm planning a long/winter heavier trip.

[Daryl and Daryl]

Eric,

I'm not sure why the framesheets are used either. I don't think they are lighter than carbon fiber stays. Perhaps it's a cost factor?

Recently some heavier framesheets (or frames) have been introduced. They seem to be running in the 11 ounce to 1 pound range. It is hard for me to justify the weight because 2 or 3 ounces of carbon fiber tubing can accomplish what I want from a frame (i.e. transfer all the weight to the hips).

Here's an example of a lightweight carbon fiber tubing frame. I use them routinely on my myog backpacks.

frame

Daryl

[EndoftheTrail]

And some "true load haulers" use both — a framesheet reinforced by two metal stays.

[Mike M]

one possible reason- they prevent packed contents from bulging into your back area and depending on the stay setup a sheet can add a little more shape to a pack

[Aaron Reichow]

Packs using heavier framesheets and no stays have been around for quite a while, and have can effectively transfer weight over 20 lbs. Granite Gear's Nimbus, Status, and Cirrus frames support 30-60 lbs comfortably. The Nimbus framesheet 8 oz IIRC and is made of composite and/or carbon fiber.

Framesheet and stay is not a dichotomy. Many modern packs use both in the same design. They're not common in UL packs because you can drop one or both depending on the weight, pad multi-use, and some sacrifice of comfort.

[Eric Blumensaadt]

I agree, some packmakers use stays on the perimeter or behind framesheets (or at least padding).

Mike> Yes, eventually stays can wear into padding and framesheets. That's why I covered my DIY aluminum stays with Gorilla duct tape, to protect the padding (and water bladder) in my Camelbak. So far, after over 100 training and skiing miles, so good.

And yes, a few companies have made fairly rigid framesheets BUT, at a weight penalty I fear, unless they are entirely of carbon fiber.

My overbuilt (7+ lbs.) Dana Designs Terraplane has Both carbon fiber and aluminum stays. But it does carry a heavy load well. It's just that I don't like to carry that load well myelf anymore…

My 2009 REI Cruise UL 60 has ovaled aluminum tubes which, being 5' 10" and 180 lbs. fits me well with its size Large harness.

To me light stays and mesh covered foam padding or an Osperey-like trampoline netting on a stressed frame is the ideal combination for pack load transfer to the hipbelt. (Actually Osprey frames are "Semi-Internal".)

[James holden]

bulge in back is baaaaad

most "mainstream" packs these days have both

[Aaron Reichow]

Wha? Everyone knows there is nothing better than a sharp corner into your back for a few miles!

[Jerry Adams]

Don't put sharp objects at the back of the pack

Put soft things

Put sharp things where they won't poke you

[Mike M]

I've heard complaints from folks w/ even their sleeping bag in the back (described as like having a big ball in the middle of their back)- I think this can easily be overcome w/ your packing style (ie sleeping bag in loosely in the bottom, etc) however, but a frame sheet prevents that as well

<– not advocating frame sheet (unless the load dictates it) :)

[Eugene Hollingsworth]

Speaking of Framsheets and Stays – Can the stays in the Golite Quest womens pack be straightened to fit a man?

Golite has a pack I want to try on clearance, but it’s the womens style. Roger C. determined the only difference between the mens and womens packs is the curve of the stays. So can I straighten them if the fit is uncomfortable? I’m thinking to just put a 2×4 inside and putting pressure on it until they bend a little.

[Aaron Reichow]

@Eugene – No reason why not. Most folks don't change the bend of their stays these days, but back in the day it was very common. Also, worth noting most men's packs still have a bend, so I wouldn't straighten it out completely.

Seems odd that the bend would be difference between the men's and women's packs. For most makers, the only substantive difference is the shape or angle of the hipbelt.

[Jeff Hollis]

If the stay is solid aluminum it can be bent. If it is a single stay, which would be my guess, then it runs down the spine, which is the easiest to fit. Over the knee will usually works works for quick adjustments.

Custom bending will take a bit more conversation.

Jeff

[Eugene Hollingsworth]

Thanks Aaron and Jeff. I'm vacillating between a 2009 Gregory Z65 being clearanced at REI for $128 if I can get Gregory to swap the belt for a medium (I’ve NOT a 28 inch waist!) and the women’s Quest being clearance at Golite.

I’m looking for more comfort than my existing pack with a 35 lb load (carry too much water and food) as I gradually work my way into lighter weight equipment.

We'll see how it plays out tomorrow.

[Aaron Reichow]

Seems like you can find granite Gear's Nimbus Ozone on sale and fs used for sound the same price… Might be work looking into?

REi, at least for online orders, doesn't do hipbelt swaps. They have your order the pack and the right sized belt and return the belt you don't need. In store, might be doable.

[Dale Wambaugh]

I would expect a woman's pack have a different sizing, where a woman's medium might not equal a men's medium, as well as different hip and shoulder spacing.

For all the time and trouble, get a pack that fits, regardless of cost. It's no different than getting a shoe that fits.

[Aaron Reichow]

+1 Dale

since it found like your not limited to $50, there are a lot of options in what sounds like your price range, especially if you but from the Gear Swap.

[Mark Ries]

My opinion is frame sheets and stays can help match the load shape to the back and provide weight transfer to the hipbelt. The frame sheet does this as it is flexable the stays must be bent although years ago after years of use I took the stays out of my lowe alpine contour 4 after hearing they should be bent to match your back and they already did perfectly. I figured that the
flat aluminum maybe would form to your back after years of hauling 55-60 lbs.in it and cinching it as tight as I did.The lighter the frame sheet the less weight it can handle and the less effective the load lifters seam to be as in my vapor trail. Carbon fiber could really only be used to stiffen the pack or transfer the load to the hipbelt as its flexable but not really enough to match your shape and it would always be trying to go back to its origional shape. Thats it for pack design according to mark dont believe a word I say

[Eugene Hollingsworth]

I have a pair of Lowe Alpine 90+15 (both bought used)that we have bent the stays to fit my boys better.

Staying in my price range and fit is becoming troublesome. I'm topping out at about $130. As to the rest of my respose, well, ugh, I think I would be hijacking Eric's thread -sorry about that. I don't want to be rude to either Eric or the guys that have responded to my question so PM'ing.

Thanks everyone.

[Author]

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