Can We Trust Bag Specs?

bag specsA couple of days ago, the folks at Tom Bihn let its  forum participants know that their long-awaited smaller Aeronaut would soon be announced.

They said it would be called the Aeronaut 30 and gave the dimensions. Only the dimensions were for a much larger bag. A few people commented on this, the thread was taken down, and put up the next day with the correct dimensions–19.7″ x 12.6″ x 7.9″. Not taking into account any internal dividers or pockets, the bag is about 1960 cu. in or 32 liters. It’s in the ballpark of 30 liters considering we don’t yet know anything about the design.

When I heard the dimensions I immediately thought of the Eagle Creek Adventure Weekender. It’s 20 x 13 x 8. But Eagle Creek claims it holds 2500 cu in/41 liters.

That made no sense. It should be about 2100 cu in and 33 liters. So I wrote to Eagle Creek to find out.  This is the response I got:

When it comes to the dimensions of our bags, we measure from the top of the surface (including the pull out handle when it’s not pulled out) down to the very bottom of the wheels. We do this to ensure that the item is within size regulation for a carry on bag through major airlines. The cubic inches provided for our products refer to the actual volume of the item, which is why it would appear that the volume and dimensions don’t correlate to one another.

What? I could understand if the volume was less than the external dimensions, but more? The only way that could happen is if the bag expands quite a bit.

Technically, they aren’t lying because the bag can hold 2500 cu in. But there is no way it can keep its shape doing so.

I checked Tom Bihn’s bags and they are all in line when comparing dimensions and volume. They basically match.

I also looked at the new Patagonia MLC Transport and they don’t even give dimensions, just volume.  (By the way, I have this bag and will  have a review up in a few days.)

Wheeled bag manufacturers vary when it comes to dimensions. Some give the dimensions that include wheels and handles, and some don’t. The 22″ roller they call a “carry-on” may actually be 24″ and will have to be checked.  Technically, if there is one airline somewhere that would allow the bag as a carry-on, it can be labeled carry-on compliant.

So what am I saying….we shouldn’t trust these companies? Absolutely not. They are all fine, reputable and honest companies that have different ways of measuring both dimensions and volume.  Rather than accepting what they advertise, get out your tape measure and calculator and determine it for yourself. And  just remember, if the volume stated is larger than the  volume calculated  using the dimensions, we’re talking about an extended/bloated bag.

Caveat Emptor.

In regards to the new Tom Bihn Aeronaut 30…..I’ve told you all I know. So far nothing has been made official and it’s too early to know if I’ll be getting one for review.

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7 Responses to Can We Trust Bag Specs?

  1. tcl says:

    I’m looking forward to your review of the new Patagonia MLC Transport. I’ve been using the Eagle Creek Adventure Weekender since last summer’s sale and have not quite gotten used to packing in the 2 shallow halves yet. I use a modified version of the bundle method so a single compartment works better for me.

  2. gafer says:

    This is a really good point, bag volume claims by manufacturers are all over the board. Red Oxx for instance appears to use the overall dimensions to come up with a volume. As you point out, this would have to be a “bloated bag” outside it’s standard dimensions.

    The only way to really know for sure the volume of a bag would be to do a standardized test using something like sytrofoam beads like those found in bean bag chairs, filling all the compartments carefully, not “bloating” the bag and then measuring the volume of beads used. This would be pretty easy but would require someone to have all of the bags being tested.

    In the end, knowing the exact volume of the bag may not be of any real value. It all comes down to how this space is allocated and whether that works for you or not. Most of the common bags used by onebagers (Airboss, ECAW, Aeronaut, Tri-Star, Patagonia MLC etc.) are plenty big. In fact, pack any of these bags completely full and you’re likely to be tilting over 20 lbs which is more than most people should carry. I imagine the same will be true for the new Aeronaut, smaller yes, but you’ll still need to pay attention to how much you put in it or it’ll get mighty heavy.

  3. JL says:

    I don’t worry about volume. All that matters to me are maximum external dimensions (ensuring that they conform to restrictions on my chosen airlines) and packed weight (ditto). Weight is really the clincher for me, given Qantas’ carry on restriction (7kg) – leaving aside whether I would even want to carry something heavier, this weight limit excludes MLC-sized bags.

    • gafer says:

      7kg? That’s tough! You definitely have to start with the lightest bag you can find with the smallest capacity you think you can get by with. I suspect you’re not in the U.S. but the Extra Small Aviator Bag from Red Oxx in Montana is fairly light weight yet has a fairly large capacity at 15x8x11. If I’m reading their allowances right it appears Qantas would allow you to bring on board two of these.

      • JL says:

        Travelling without checked luggage on Qantas (and other airlines with similar hand luggage restrictions) has really redefined the way I think about packing. Distributing the weight across two bags is the key here (one main bag and a smaller personal item). But if you apply the 10% rule (ie try not to carry more than about 10% of your body weight), 7 kg is really more than I should be carrying anyway! I don’t think “how can I carry the most possible?”, I think “what is the least I need to bring while still looking presentable at my destination?” Then it’s just about planning. And I’ve found with good planning, surprisingly few packing “sacrifices” are required (subject to purpose of the trip)!

  4. Ralph says:

    i also don’t really get into volume, but weight and exterior dimensions. even if a bag isn’t stuffed, a mlc sized bag, assuming it keeps it’s shape is big; flying non-us carriers especially.
    the weight is always the big deal. if packing includes electronics (and/or laptop), or anything ‘heavier’ than clothes, or ‘heavy clothes’ themselves that cannot be worn, the size of the bag becomes less relevant as the carrying weight becomes the issue.
    same reason i don’t often use my skytrain unless by car travel. it’s built like a tank, but a) i don’t need a tank and b) its heavy. lifetime warranty is great, but more often than not, my preference changes. not really sure i want to use the same bag 40 years from now, but i certainly don’t want it to break in a couple years.

  5. Lewis Clark says:

    Invoking Betteridge’s Law.