hey ATrain, how does weight translate to cube size. i am downsizing and in search of perfect cube size pack. i have randomly decided for what i need, a 2900 cube pack might work…does that make sense? gonna carry my pack to my fav. dealer and try the new pack out in the store loaded just to make sure, but i think i cinched my 5400 cube kelty down to nothing and the extra weight of the pack was needless and ultimately bulky for what I had in it.
burn
Sort of depends on when you’re leaving; March or Winter…also on how comfy you want to travel. If you think you have everything you need to start, which will be more than you end up with by at least Hot Springs, take it all to the outfitter on an off day and start stuffing. Also bring five days of food, that will take up as much room as your sleeping bag so about 1/3 of you pack. For example; I have a 4200cu Gregory Thru-hiker…really, they don’t make them any more but the name is cool. With a 0* down bag, five days of food (you’ll never want to carry this much but sometimes you have to), camp clothes, tent if you have one, most folks do for at least the bugs unless you like the snorers, camp clothes, unabridged Roots novel, cook gear, water filter flashlight t/p Pocketmail Platypus pack cover. All that’s going to get a little tight in a small pack. When spring hits and you ditch your winter bag or lighten to a fleece blanket you’ll have a ton of room for more food. It sounds weird but if you think outside the…pack/box? and make the gear fit the pack instead of the pack fit the gear you may end up with a lighter load. It takes even an experienced blah blah blah like me a while to trim some more. I still find a new lighter smaller better piece of cool stuff that I can’t do without. But I won’t give up my camp chair. If you don’t use it every day on the trail leave it home. Then see if each gear item can go small and lighter if that’s what you want. We made the mistake of using older gear that we knew would get trashed…it weighed to much. By Neels Gaps we had new rain gear at half the weight and swapped out old synthetic bags for our two pound summer ones, yes it was February but that’s another story. You have your startout gear list posted and when you leaving?:nerd
Bushwhack
Oh yeah, the weight of the pack itself doesn’t matter to much with all these new pack designs but its how it fits. My pack I think is five years old and weighs a shade over 4#s. It’ll also carry 10-80pounds if I need to because of the suspension. Not light by todays standards but it fits like a glove. You can get a nice 1 lb jobber but your shoulders will die. Look for a good frame sheet and suspension over pur weight.
BW
I just received my Mountainsmith Auspex yesterday 4200cu/3lbs,7oz and it’s JUST barely large enough. My sleeping bag takes up 1/3, my food and cookware take up about 1/3 and my winter cloths take up the remaining 1/3. I have my tarptent and sleeping pad straped to each side of the backpack behind the compression straps on the outside with room enough for a fuel bottle and water bottle in the side mesh pouches. The tope pouch contains map, firstaid, toiletries, etc… Total weight with 3 liters water and 4 days food is around 30lbs. Summer weight will be around 23lbs. I don’t see how a 2900cu pack could possibly hold enough for a 3 season pack without straping a LOT to the outside. I saw a few people doing it but they carried no stove, no sleeping pad, a summer bag, and a tarp. They must be a lot tougher than me to hike like that, just to save 5-6 lbs.
Nooga
The Mountainsmith Ghost is 3100 cubic inches and weighs about 2 lbs 6 oz. My husband used it, it was pretty full in March with the winter clothes, but had lots of extra room in the summer. Granted, we shared some pack weight as a couple, (only had to carry one stove etc.) but we started with a 2 man tent and a few other “heavy” things. Two of our solo-hiking friends also carried the Ghost, and while they hiked light, they did carry stoves, sleeping pads etc, and even winter clothes in March. So, I definitely think it can be done. So, you might want to check out the Ghost, it packs up funny but is a good sturdy pack. I’ve also heard great things about the Granite Gear Virga - 3200 inches for 1.5 lbs weight.
Besides weight, bulkiness can really affect what pack works for you. For example, sythetic sleeping bags are very bulky and might necessitate a roomier pack.
Good luck
Jitterbug
You guys have that extendable spindrift collar on the upper opening of your packs? I might be the only one since my Thru-Hiker is actually an expedition model. That extra collar is a full ten inches high so I can expand that pack to 5400 I think. It’ll swallow a whole tent, two six packs or a cat. I was going to cut it off but nah, it saved my stuff many times for the few ounces it weighs.
Straping gear all over your pack isn’t much of an option since it throws the center of gravity all to hell. If its a foam pad no biggy but we saw this dude in Va with a two pound camcorder hanging OFF the bungi at the bottom of his pack. It was going gaboiny gaboiny like a cat toy as he walked. Funny but sad.
Bushwhack
My pack could carry a total of 2620 cu in. In the beginning, when I had way too much to carry, I had to strap my sleeping bag, tent, and sleeping pad to the outside.
Once I shaved down to the bare essentials, and added winter gear at the end, everything fit inside my pack, except for my sleeping pad.
As long as you stick with only what you need, then 2900 should be fine.
bearbait
Burn, well you got some excellent advice. Jitterbug makes a good call on the Ghost. That is where I was headed 
I used it for about half the AT and really liked it. Its about as close to a “square” pack you’ll get. Its a strange design made more like a school bookbag/knapsack than a rucksuck that loads from the top like most standard packs. BushWack is right. You just need to find the pack that fits you and your stuff correctly. Bring all your gear to the outfitter before trying on packs. I’d also recommend the granite gear vapor trail or even the virga if your going seriously ultra light. The P2 has also got some great reviews.
I started march 1st. It is entirely possible to start the trail at this time with a 3000 cu inch pack, but as Nooga shows, it is difficult. From what I know now I could easily do it, but I had no clue before starting. I started with a 4500 inch gregory and ended up downsizing.
As the rule of thumb goes…The more room you have, the more you will fill.
One last thing. With a small pack you can and will have to lash things onto it as Bear bait suggested. That is something to keep in mind. I’m not a big fan of tying/roping/hanging things from the pack. You’d be suprised how many flip flops I found along side of the Trail. Might be something to think about.
Lets us know if you got other questions.
A-Train
I am leaving amicalola feb 29th, springer march 1st. I just did GA, which they say is now 80 miles, so my total hike was 97 or so miles, and i had way too much food, way too much junk, and i had it cinched down pretty good. After, i realized I could do with much less and resupply more. I already tie my mat to the outside, but will add a tent/bivy, or tarp and camp out…the mice and the skunk experience is something i don’t think i’ll want every night.
Waldo SOBO '03, a source of great info and encouragement, convinced me that I could shave 2# or much more just in pack wt. and not sacrifice suspension & comfort. I’m lugging a Kelty RedCloud 5400…nice ride, but 5# 12 oz. you understand.
I am also gonna add Leki poles…will the lower cost 2 pc ones work or should i go for broke and get the 3 section ones?
burn
It sounds like you’re headed in the right direction…going with a smaller pack. Why go with more than you really need?
With the preface that I realize that what worked for me may not work for others, I found no need to carry that many extra items for colder weather. I sent home a vest (1#) that I hardly ever used. Replaced my “heavy” guide pants (1#) with light (5 oz) rain pants. (Some hikers had no long pants whatsoever and used long silk underwear bottoms under shorts in colder weather) Replaced heavy vented parka (20 oz) with light hooded rain parka (5 oz) Used a 1 oz Walmart emergency parka many times…may even have been able to get away with this as my only outer upper body rain gear but I didn’t have the guts to send home the 5 oz parka.
Carried my Pategonia “power stretch top” the entire hike. Even in the summer I found it useful from time to time for early cool mornings. It was my “warmest” clothing item for cold weather and was “worth its weight in gold.”
Bought a Feathered Friends down bag that weighed about 2# and used it the entire hike. I saw no need to switch to a “summer” bag. Used a silk liner and slept on top during the few warm nights. (BTW, developed no bad stench with the silk liner and wearing long johns to bed.)
Bushwack mentioned the extendable/expandable top feature on his pack…I loved it in my P-1 pack. It wasn’t absolutely necessary, but made it so so easy to pack when leaving town loaded up with food.
Leki poles…I loved my titanium 3 section ones. Banged and bent them up pretty bad but they lasted the whole hike and am still using them…hope to get them repaired at Traildays.
Sounds like you’ll do fine…good luck!
Skeemer