Who decides what size a pack is?

[sapper1]

I have had numerous rucksacks over the years ranging from 10-120L and they are all different.(surprise,surprise).
What they all have in common is they are all measured in litres.Now my problem is who measures this and how do they do it?I have had a 30L sack that held more than a 50L sack,there seems to be no standard size for the litre.
My plce bergan with pockets seems to hold less than my vulcan without pockets,my sabre 45 with pockets holds everything in my plce plus lots more room,enough for another sleeping bag.
My plce is upposed to hold 120L with pockets,there is no way that it holds the same amount as 6 jerry cans.Try seeing how many 5 litre cans will fit into your sack and see if it's correct,I have ordered a 90L dry bag when it arrives it's going to go in my sacks and get filled with measured water to see how close the manufacturers sizing is.
I think I might have a surprise on some of them.

 

[tomatoevousparlour]

Sounds good, I got a 55l pack and a 85l and there is no way 30l differnce between them

 

[Sniper]

The size of a rucsack is one thing I never bother with, I just look at the size and whether I can fit all my junk into it. Only problem with this method is cos I have a big un I cram a lot more into it which I don't need, but damn I'm comfortable with me extra toys.

 

[DKW]

Dont you think its more to do with poor packing, and less with measurements done wrong?

 

[sapper1]

Subtle!
But no the same kit fits in one bag with room to spare but not all will fit in another that is supposed to be bigger.
I pack poorly no matter the size of sack.

 

[DKW]

Sapper.
What i mean is, that i can see a very reliable state of packing with the young scouts i have. It goes by the name: Cub-spring.
Basically the fact is, that nomatter what size bag they have, they wont be able to pack all their gear into it, because they pack poorly. Sort of if they where packing springcoils or something.

I do it too on occasion. When i use my big bag, i won't compress and fold my gear as well as i would using the small bag, in fact i wouldn't make sure to fill all gaps and tiny empty spaces neither. Thus giving the impression that the big bag is smaller than it should be.

Yes. I am almost certain that some manufacturers do give the wrong volume. But i am almost just as certain that it ain't that bad. It is just us who are prone to use the volume badly, or the volume that is placed badly. Don't know why, but i know it is so.

 

[Nagual]

Yeah! I thought the same thing when I got my Gourdon which is ment to be 30ltr and I noticed it seemed to hold more than it should when compared to my 85ltr Gelert. The Gelert holds more, true - but not much more, certainly not anywhere near double or even 1.5 as much...

I suspect its the same people who make up erm I mean work out sleeping bag 'comfortable temperatures'..

 

[dannyg]

Doesn't the given volume for a rucksack mean that the volume in total of every pocket, rather then just usable volume in the main compartment, for instance, if you were to get 2 65L rucksacks that you feel are a different volume to each other, and filled every compartment with water, wouldn't they be both 65L?

 

[Jaysurfer]

I think thats about right Danny ^^^^^^

Manufacturers are starting to call their bags 40+10 etc etc so that tells you that you have a 40L main compartment (including volume of the top pocket where wet weather gear or lunch is usually kept) and then 10L devided up over the two side pockets so technically 5L each side.

 

[stevesteve]

My plce is upposed to hold 120L with pockets,there is no way that it holds the same amount as 6 jerry cans

Don't try it Sapper1 you'll only end up with fuel dribbling down your back

Seriously though I've just been through looking for a ~40L pack. I agree that packing is an issue and when I have taken my plce 120L bergan out it is too easy just to bung things in as it is so huge. I have to say that standing in outdoor shops in London looking at the racks the litre cetainly seems to be a variable unit!

Cheers,
Steve

 

[Karl5]

The brands all measure the total volume of a bag, but that's about the only standard for measuring rucksack volumes existing. There are still no standards set on HOW to measure the volume, so the manufacturers use different methods. I.e. the value for e.g. 45L will differ from manufacturer to manufacturer.
Example:
Ping-pong balls have a lot of dead space between them, i.e. they wouldn't fill up every nook and cranny of the rucksack.
Dry beans don't have too much dead space between them, so they would fill up every nook and cranny of the ruck.
I.e. 45L of ping-pong balls would need a larger rucksack to fit them than the beans, simply because the balls need more dead space around them to get into the ruck.

 

[Minotaur]

This is just scary. Nearly posted this myself. Just worked it out for my kit, so I had an idea of what Ruc I actually needed.

I think thats about right Danny ^^^^^^

Manufacturers are starting to call their bags 40+10 etc etc so that tells you that you have a 40L main compartment (including volume of the top pocket where wet weather gear or lunch is usually kept) and then 10L devided up over the two side pockets so technically 5L each side.

Those packs have expansion straps so you can gain an extra 10L. Some sort of bellows pockets on the side or something like that. They also list the removable side pocket/daysac rucs like this.

The reason for litres, is what other volume are they practically going to use? Customers can just get their heads around them. Most other volumes are cubic something, so a little hard to picture. In other words I think it is marketing more than anything else.

No water involved, a litre is a litre, it is a measure of space, and nothing else. The reason for different sizes, at a guess, is rounding down, and all the pockets.

I have on my webbing belt - two kidney pouches, and 8 Alice pouches, and that only works out to 12L.

I like the climbing style of one big space, for packing it is so much easier.

Want to pack right, carry it, or get them to. Hiking makes you look long and hard at all the extra crap you carry. You could do a weekend or week hike, and every morning they can dump stuff out, but once gone they cannot go back for it. At end go over what left in pack.

 

[big_swede]

It varies a lot between brands. Some actually state 'compressed volume' or something similar. There were a thread about this on a swedish outdoor forum where people tested their bags. I think the brands that were closest between the stated volume and real volume were sacci, norrøna and bergans. Arcteryx and some other brands were far behind. Some models of bergans packs were actually bigger than stated (noteably their monster pack powerframe).