Photo is the REI 40-L daypack.
I've done reading on the topic of daypacks. I have always used my antique Osprey daypack (made in Dolores, CO) which is about 20-liters. With a replacement waist belt which my shoe repair guy fixed up for me for $10, it sits right and holds anything I might need for an ordinary day hike. (I think any pack without a waist belt is a terrible idea. I have also found that a proper fit and tweaking the adjustments makes a big difference. It has to sit on your butt.)
I bought my Osprey pack in Telluride on a ski trip with the kids. Needed a place for them to put spare winter clothing in as the temperatures went up and down and as snow came and went during the day.
Mrs. BD took the liberty of buying me a 40-Liter REI daypack for our recent Hebrides hiking trip. It fits well, but holds far more stuff than I am ever likely to need other than for lengthy winter hikes.
In fact, it could function as a smallish airplane carry-on. These days, half the people on international flights carry backpacks. They have become standard tourist items, but who needs a backpack or daypack to walk around Florence all day?
Let's say the usual day hike off the beaten track is from 4 to 8 hours. What do you need in the pack? Some liquids, snacks, maybe a sandwich or two, some rain pants and waterproof jacket, a trail map or travel guide, a first aid kit and some blister packs, a wallet, binoculars, a little camera or iphone, perhaps a 2-way radio if remote, maybe a place for hiking poles - and empty space to stuff layers that you might not want as the day warms. A box of ammo if hunting in the wilderness.
Shouldn't a 20-L pack be able to handle that, and more? Unless it's warm weather and you are carrying several liters of water, or unless you are playing sherpa and carrying stuff for other people.
Here's The Ultimate Backpack Size and Volume Guide
I think the Osprey 20 L pack is a good daypack choice.
We're about to plan our next wilderness hiking trip (day hikes only, thank you, with fluffy towels and hot water at night), so I will decide for sure whether 40 L is overkill.
If you are a regular day hiker, what size do you use, how do you use it, and what do you put in it? And if you would want a 40-L pack, why?
