If you plan on carrying all of that stuff, disregard my suggestions. Most cycling-specific backpacks (outside of messenger type backpacks) are designed for smaller loads and "larger" ones hold about 1300 cubic inches of stuff.

For what you're describing (a full day's worth of provisions), your best bet is the Chrome or else posted that is something similarly sized.

With as much time as you spend walking, carrying your day's necessities, personally I would avoid a single strap courier bag, I think they are way top uncomfortable for prolonged off bike/large load portages. I'd go with a two strap model of some kind. Have an uber yard sale, then drop $240 on a Bailey Works "Citizen" @ 1,764 cu. in., or for your needs, the "2-Strap Work Pack," which tops out at 3,7780 cu. in. for a mere $300!

All of my options are 2 strap packs. Forget the garage sale I need to sell the friggin house to buy these things. 300 makes the chrome sound like a deal at merely 200 dollars.

I have an ancient very large Timbuk2-- I seem to be able to carry a ton in it without serious collarbone discomfort-- no 2nd strap. And I'm not really all that tough.

Liter of water, Vacuum sealed old glass thermos of coffee, lesson planner and grade book, new york times, rain pants, multi-tool, work clothes, etc...

and when it's errand time, I can fit a 1.5L bottle of red fir my wife and a 12 pack of beer (out of the box and the bottles tucked in... or even the whole 12 pack if there's no wine.) on top of all that.

I guess it depends on what you draw the line at "discomfort."

Sorry, no recommendation to offer other than giving one strap messenger bags a serious try.

Hey man, I can't even BUY a house because of this bag, but it's big enough for us to live in so I guess that's fair.

I used to constantly switch bags when I rode for my daily commute. I was always in search for the best, most comfortable, waterproof, versatile bag. Tried lots of backpack and messenger options. I finally decided to bite the bullet and get a Chrome bag (or actually, my wife did for my birthday).

I haven't switched bags even once since. :thumb:

I just picked up a MissionWorkshop Rambler and it seems perfect for your needs. The way it opens up to swallow anything but is compact the rest of the time is pure genius. I've had it for four days and keep commenting to myself how incredible it is. It has replaced all of my Chrome two strap bags. It is way more comfortable and practical on and off the bike. It's made by the orignal founders of Chrome (they sold Chrome two years ago) and is the bag they have been wanting to make for a while.

I know you want to try local, but given your requirements and your goal to get a back that will not need to be replaced soon, check this one out -- you can always order it and return it if you don't like it. Here's the link: http://www.missionworkshop.com/.

Have you looked at any of the Osprey packs? Theyre a little pricey but high quality. Another suggestion is what I decided to go with for my equipment needs. I only have a small under-seat bag and don't want to go to panniers (yet) and sometimes need a little more room but I don't think my DaKine skate pack is form fitting and (I guess) "technical" enough for anything over a mile. I picked up a Hydrapak Big Sur from Bonktown. Its pretty small, but I usually don't run into much hydration issues so I pulled the bladder and use that as the main compartment. Doubles the amount of stuff I can carry. You obviously need something larger, but look at larger hydration packs like the H.O.S.S., they're usually pretty tough and if you don't need the bladder pull it and use that compartment for more carrying capacity!

I just picked up This Novara Commuter Backpak at REI.
Looks great for my needs.

http://media.rei.com/media/nn/af0077...9d04a15fb4.jpg