And there it is...once one gets beyond minimum safety considerations, it does, seemingly, all come down to comfort..as I think all lightweight backpacking considerations do. What TomD outlines above, substituting a medium weight jacket for the parka and adding insulated pants (topic of the OP), is my sleep system.
Here's what I think is key for me. I haven't added anything to my backpack and I took out the bulk of an approximate three pounds of sleeping bag. The result is I have integrated my shelter and clothing with what's left of the original sleep system, i.e., the pad. Ryan Jordan of BackpackingLight published a 2003 technical white paper on this very subject but darn if I can find it on the 'net.
I always sleep in 'thermals'...in a bag or out. There are several reasons I do this; extend temp range of sleep system (bag or not), keep the bag/quilt clean, the SmartWool feels so much nicer than the the feel of the bag on bare skin, etc. Effectively, all I've done is add a layer of insulated clothes (jacket and pants). Since I started using this sleep system coincident with my start with hammock hanging I can't address the individual comfort level...all I can say is that combination has been sweet! There's been minor, spinoff benefits too...not having to wrestle a bag in the hammock, not having to get dressed for a frigid nighttime Nature call, no need to dress until the Sun warms the morning up...
Comfort and individual perspective. Rather than feeling "wrapped up in clothes all night" I relish the feeling of not being restricted by a sleeping bag. And the three pounds I left at home is a major percentage of what is now my approximate 15lb base weight...
Everyone is different and they face different trail conditions. The key is to get everyone to think differently from what they have been locked into. A bag is just one of many options; a backpacker's 'big three' is not a Holy Trinity.
"...inalienable rights...include the right to a clean and healthful environment..." Montana Constitution
I've considered it myself. I have been sectioning the PCT during my summers away from school. I think a lot of the responses you received deal less with ultralite hiking and more with hiking in general so maybe I can help there. Weather does play a part, I would consider the setup for some desert-rat running but not for the northern mountains.
my thoughts Pros less weight: (pants: 6-12 additional oz) vs (bag: 20-30 additional oz) less clutter/chore: Fiddleback mentioned this as well. layer: can quickly be pulled on when resting Less space: smaller pack Flex: Someone (sorry I forget who) mentioned this as well, you can own one lighter bag and use your jacket and pants to extend the temp range.
Cons colder: I imagine this to be like wearing gloves vs mittens, the fingers can't share heat in gloves, similarly the legs and arms can't share your core heat stored inside a bag.
My rambling thoughts... I hope they help! I'll be following the thread and I would love to see others thoughts as well since I've been kicking it around for a few years myself. I just can't pull the trigger on a several hundred pair of pants that may or may not work out!
Surprised it has not been mentioned, but at one point, there were down pants that could be zipped at the legs to make an "elephants foot" half bag, significantly reducing the surface area problem, and a down jacket that zipped to the pants to prevent drafts. The "elephants foot" half bags are still available, I know, but I haven't seen the pants for awhile. If one can sew and handle down, one could make a pair.
I remember being quite interested in these at one point, but they were way out of my price range. The jacket and pants together also weighed slightly more than the sleeping bag I was using.
The system had a French name (translated as Elephant's Foot) and seemed aimed at the climbing community.
Since this approach seems to have largely disappeared, I suspect it was not fully successful, but do not know what the drawbacks were.
I personally prefer not to have all my critical insulation eggs in one basket, as it were. Also, having insulating clothing separate from my sleeping bag allows me an extra margin to stay warm even if the temp after a summer storm drops into the single digits, not completely unusual in the high Rockies (just ask W_D). Your Mileage May, of course, Vary.
Edited by OregonMouse (02/12/1702:04 PM)
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey
I happened to order some insulated pants yesterday, and here today I see a thread about them.
My reasons included being able to wear them in camp before sleeping, stretching the temp range on my sleep system and for making overnight nature calls much more bearable. I'll keep the quilt, since it's pretty small/light. And I'd have a margin of error if things got colder or warmer than expected. I guess the gist is I'm also trying to shift to wearing more clothes than getting a warmer quilt and insulated pants is a step in that direction.
Most of the time, we are in RMNP at sites that don't allow fires, so evenings in camp just get cold. And it regularly gets down to the 30's in summer at the higher elevations, or colder.
But if a herd of angry raccoons started gnawing on my hiking partner (in his hammock, several feet away) wearing warm pants would mean I'd be less likely to just yell, "Hey, can you keep it down!" from my warm cocoon. I'd actually climb out of the bag and yell.
But seriously, folks... I was surprised to see how few choices were out there for packable down or synthetic-fill pants. I spent about a week scouring the internet for deals or lesser-known brands, but ended up nabbing a pair on sale.
Loc: Central Illinois near Springfi...
I've got some of the M65 Pant liners for cold weather lounging. I had not thought about sleeping in them, although there is no reason that I couldn't. They are cut short to be worn with boots and they are cut very generously, so they aren't going to fit in any close fitting pants. Somewhere, I've got an old surplus mountain shell pant that should work with these liners. They are made to button into the cold weather pants that they were made for. This winter hasn't been that cold around here, so they haven't been outside yet.
Loc: Washington State, King County
FWIW, I've had a pair of synthetic insulated pants for years, and while they seemed like a great idea when I ordered them, in practice I always find that the weight and bulk keeps me from carrying them. I'm more likely to throw in a pair of silk longjohns plus very lightweight rain chaps; the combination is lower weight and lower bulk and more flexible.
I'm not saying that I never use them, just that the right combination to do so isn't common based on my personal hiking style, trips that I take, etc. So maybe they will turn out to be a wonderful purchase for you!