4:13 p.m. on August 16, 2010 (EDT)
I'm new to this forum, hello everyone.
I think that other than eliminating extra weight from your gear and stuff, the most important thing to being light and mobile is:
1. Losing weight in you body like the last poster said. I don't have that option, I'm already light enough now. But I did lose 3 lbs (just from hiking) and it made a big difference!
2. How you pack your pack.
I'm one of those old-school backpackers, who started with an external frame pack in the 70's. But I have evolved with the times and always attempted to keep my gear light and minimal, with minimal purchases. When I finally decided to spend the bucks and overhaul my gear, I read the backpacking light books, surfed all the light gear sites, read the reviews, and tried out the lightest stuff. Most of it was too expensive for me and I never found a pack I liked, so I bought silnylon and made and designed a whole bunch of my stuff, including my pinnacle of obsessiveness, my backpack itself. It is designed for other women or anyone who wants the weight on the hips, and hates the pack pulling backwards on the shoulders. It has all the bells and whistles, can go as high volume as you could ever want, and weighs 1.5 lbs. I have also built my bivy, poncho, wood stoves, and doggy pack, poncho, and doggy sleeping bag/jacket. It's been fun, and satisfying.
But I invested in the sleeping bag: less than 2 lbs for a 15-degree bag, 850 fill down, at $300 on sale, with dwr for dew and tarp overspray. I sleep really cold, and need lots of warmth at night.
So I got down to the "ultralight"-defined 10 lbs baseweight (everything except food, water, and fuel, bear canister, and what you wear during the day). Since then, I have added weight, mostly to make better time efficiency, and add a few "luxuries". Like the wood stove takes a long time to use, so I bought the lightest snowpeak gas burner and the smallest fuel can lasted me over 6 days on my last trip, and I bring the wood stove as back-up. And I bring a little under a lb of fishing gear. Sometimes a liter of wine to share. I still double the use of my poncho as shelter. That saves me at least 1.5 lbs even with the lightest of solo tents. (In summer)
I'm up to about 12-15 lbs base weight depending if I take fishing gear and bear canister. Then I carry up to a liter of water (2 lbs), and AquaMira or Steripen to purify (included in base weight). A small can of fuel. And about 1.4 lbs of food per day. My last trip was 6 days and I walked away from the car with 24 lbs pack including a liter of water.
But really, the thing that seems to make the hugest difference in bp comfort and mobility is HOW YOU PACK YOUR PACK, and HOW YOU WEAR AND ADJUST YOUR PACK. I've been recently leading trips, and teaching folks about lightweight gear, and have had the opportunity to repack a few folks' packs for them, and show them how to properly adjust all those straps. And where the pack should sit on your waist and/or hips. Those that have welcomed that (it's amazing how many have refused), have been floored by how much difference it made. Their packs felt lighter, and road more comfortably, without ever removing an ounce of their gear.
There should be books about that, or at least a booklet. Is there one? Maybe I should write one. Oh wait, this post is so long it almost is one. Hee hee. When my pack is packed right, I can strap on the hip belt, and there is NO pulling back on the shoulder straps. With the tiniest forward lean, as if you're hiking uphill, I can take the shoulder straps OFF my arms and the pack doesn't fall backward. Other packs aren't quite this great, but they're a LOT better if properly packed. The weight sits on the hips over your center of gravity.
The key is to pack heavy items next to your back, and lower down, with lighter items away from your back. And to pack your pack with items pushing your pack out WIDTHwise and minimizing how far BACK items push the pack out. You don't want the pack to assume a cylindrical shape. You want it to be kinda wide and flat. And better a bit higher than sticking out behind your body. Closer to your body it can be, the better it will ride. If I have to use a bear canister, I fill half of it with dense food (widthwise), and the other half with something fluffy, like extra socks, or long johns, and pack the heavy half in the pack close to my back.
Two men I know weren't comfortable with their packs, and had unbuckled their hip belts and were carrying all the weight on their shoulders. After I adjusted their packs for them, and showed them where to ride their hips belts, and how to tighten and loosen the various cinch straps to pull the packs closer to their backs, they said it was like night and day.
Sorry for the long post, I hope this was helpful.