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Backpacks

Extension collar

Also called expansion collar, spindrift collar

What is an extension collar?

An extension collar is the fabric tube above a top-loading pack's main compartment, closed by a drawcord. Rolled down it does nothing; pulled up it adds capacity, typically 5 to 10 liters beyond the pack's quoted volume.

Extension collar at a glance

Typical extra volume
5 to 10 L
Best for
Food-heavy first days, bulky canisters
Cost of using it
Higher center of gravity

Where to find it

Look inside a top-loader past the point where the pack body ends and you'll usually find a lighter tube of fabric continuing upward with a drawcord at the top. That's the collar. Most of the time it's folded down inside and you never think about it.

The day it earns its keep

It earns its keep on the day you're carrying more than usual: a bear canister, a week of food out of a resupply, a friend's share of the tent. Pull it up, cinch it, let the floating lid rise to meet it, and the pack takes another 5 to 10 liters without complaint.

What it does to how the pack carries

Using it changes how the pack carries, though, and not for the better. Everything you add sits high, above the frame's best load path, which raises your center of gravity and makes the pack want to steer you on uneven ground. It's the right tool for the first two days after a resupply and the wrong one as a permanent arrangement.

What this means when you're choosing

  • Whether the collar is a full tube or a token few inches
  • A floating lid, which can rise to cover a filled collar
  • Compression straps that still work with the collar rolled down

The common mistake

Treating the extra capacity as free

Everything the collar holds sits high and behind the frame, which is the worst place for weight. It is there for the day you come out of a resupply with six days of food, not as a reason to buy a smaller pack.

Common questions

Does the quoted pack volume include the extension collar?

Usually not, though brands differ and a few quote a range that does. If a 60 L pack is advertised as 60+10, the collar is the +10.

Should I use the collar on every trip?

No. Packing high makes a pack unstable, so use it when your food carry genuinely needs it and roll it back down once you've eaten a few days' worth.

Where this comes up

Guides on Tom's Hiking where extension collar changes which product is right for you.

More in backpacks

Load lifters

Load lifters are the short straps running from the top of the shoulder harness back to the top of the pack frame. They pull the load in towards your body so it stops levering you backwards. They don't carry weight themselves.

Hipbelt

The hipbelt is the padded belt that wraps your pelvis and transfers pack weight onto your hips instead of your shoulders. On a loaded backpacking pack it should be carrying most of the weight, often quoted as 70 to 80 percent.

Framesheet

A framesheet is a sheet of stiff plastic in a pack's backpanel that spreads the load across your back and stops contents from poking through. It's lighter than a frame but gives you less vertical support.

Internal frame

An internal frame is the structure hidden inside a pack's backpanel, usually one or two aluminum stays or a perimeter hoop, that carries weight from the shoulders down to the hipbelt. It's what makes a pack load-bearing.

Suspended mesh backpanel

A suspended mesh backpanel stretches a taut mesh across a curved frame so the pack body sits away from your back with an air gap behind it. It's the coolest-running backpanel design and the one that holds the load furthest from your spine.

Pack lid

The lid, or brain, is the padded flap that covers the top of a top-loading pack, usually carrying one or two zipped pockets. A floating lid is one attached by adjustable straps so it can rise as the pack is overfilled.

Panel loader

A panel loader opens with a zip that runs around the front of the pack, so the whole compartment folds open like a suitcase. The alternative is a top loader, which you access through an opening at the top.

Shove-it pocket

A shove-it pocket is the open-topped stretch panel across the front of a pack. It has no zip, so you can push a wet jacket or a map into it one-handed while walking, and pull it out just as fast.

Load rating

A load rating is the weight a pack maker says a pack carries well, usually given as a range in pounds. It describes the frame and hipbelt rather than the fabric, so exceeding it doesn't break the pack, it just moves the weight to your shoulders.

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