Hi everyone

In my quest for a light pack I'm thinking about losing the 2.75# sleeping bag I have & at first was thinking I didn't need 1 at all, but now I'm more leaning towards going with just a lightweight sleeping bag liner. I was just wondering if anyone else has done it or maybe if they have a liner or have used 1, what your thoughts were on it? I'll bring the sleeping bag when its cooler out, but am planning this for a spring/summer/fall pack, so the cold shouldn't be a huge issue. I just don't want to spend the money on 1 I guess if it doesn't seem like they're anything more than a windbreaker jacket...

This is going to depend on where you are hiking.

I personally won't leave the trailhead without gear that's comfortable to below freezing. I could survive without a 20f quilt and pad, but I demand comfort. And it snows on me sometimes in summer.

It would help if we knew where you do your hiking. When I was in the Army and training in the SE, I would often just carry a poncho liner. Of course it seldom got below 75 at night there in the summer. Now I hike in the western mountains; it can get to freezing at night even in high summer and I won't go out without a bag or quilt warm at those temperatures. Location matters.

It shouldn't be cooler than 40ish on a cold night, in & around ohio. I'm a beginner & not planning to hike up mountains...while asking about a bag liner as being sufficient lol. I'm just looking for general information & opinions on the liners through others' experiences

One way that you may be able to test it yourself is to find out the thickness of the liner you are thinking of and ,at home, wrap yourself up with a blanked of similar thickness (disregard the weight) in similar temps (do that sleeping on the floor on your mat or outside not on top of your bed) and see how it feels for you.
You only get more noticeable insulation from the emergency type bivvies (mylar type) but then condensation comes into play and you may not want to do that night after night.
And that is why they are called "emergency" as opposite to "regular".

It's an approach that may work around here, and we're blessed with numerous state parks that make it easy to test. Take your liner to a nearby park, stay in the car campground, and "simulate" a backpack trip using it. I'd suggest a full day's hiking and a backpacking menu, to create the typical amount of calorie intake, dehydration, and tiredness you'd have on the trail. Then use only the liner and your pad, and see if you stay warm enough. The key: your nice warm sleeping bag is in the car; if the experiment fails, you can go get it. That will let you establish the limits for using the liner, without requiring you to go to the nether regions and freeze your nether regions off.

I tried this with a fleece bag, and found the limit to be around 60 degrees for a nighttime low; anything lower, and I want an actual sleeping bag. Your results may be a bit different.

Sorry...test post to see if sticky topic means what I think it means.

But I will say liners are not very warm. Unless you are in an area that does not drop below 75 degrees F, you would be better served bringing a wool blanket.

I know of three options.
1. wool blanket
2. fleece blanket
3. wooby (military poncho liner)

The benefit of a wool blanket is that you can sleep next to a fire to keep warm.

Whether it works depends on your system. How much clothing insulation do you have? What type of shelter?

A fourth option is a 40F quilt. Depending on the insulation, it will be warmer and lighter than the wooby, unless you use the same insulation as the wooby.

For whatever it's worth, I used a fleece bag liner (REI) on my first thru hike of the AT. I used it roughly from Damascus to the end of the White Mountains (kept it because I was using the huts). I was also carrying a fairly heavy, weather and bug proof bivy (Integral Designs). I had long undies available, as well as a wind jacket, rain pants and light fleece jacket (as well as hat and gloves), and I sometimes wore them all.

On the other hand, especially starting in the Skyline Drive area and continuing through NY and NJ, I tended to sleep in just my hiking clothes, on top of the fleece, often on top of the bivy itself. Occasionally I would put on the rain pants and the fleece jacket (still on top of the bivy). This worked well for me except for one night when I had to make a very fast dive into the bivy when it started rather suddenly and (for me) unexpectedly to pour down rain.

I have more experience than I ever really wanted with the military poncho liner.
It would be more than one would really need in the period listed above, but unfortunately, it was nowhere near enough where we were using them (hint: two countries involved, same name).

Brigade Quartermaster made a better one with a head hole so you could actually use it as a jacket and with better insulation, but I never bought it. Several times thought about asking Jacks R Better if they could make a down one. Interesting idea (but I would want it paired to a modern poncho).

Hope that's useful. Best, jcp

Stickie means a post stays on top where we hope people will see it and read it.

Instead of a bag liner, I would consider something like an overbag. I have an MEC Emperor Penguin (an earlier version of the current one) which is not only good alone down to about 50F, but can be used over a regular bag to add about 10F to its rating. It works. The advantage of the overbag is that it has a cover so it can be used as a light bag.

What about this ?

Oooo, sweaty.

Didn't Samoset get one a few months ago?

Anyone want to test if the zipper on this version vents?

Thanks everyone for the helpful input! & thanks tom I didn't even know OVERBAGS existed? I will look them up right now

I have tried several slp bags and currently own a half dozen of various ages and weights. My 'go to' bag nowadays is a 1 lb, 2 oz ounce (800 grams) LaFuma Warm 'n Light ($150 or so) down bag. Weight and warmth are proportional in any well designed bag. And you will gain about 45% in weight by going to synthetic as opposed to down. I have used both types hiking and climbing in various conditions, WA, AK, CA, AZ and I have always been able to keep my down dry, or dry enough to maintain plenty of warmth. http://www.backcountry.com/lafuma-warmn-light-800-sleeping-bag-30-degree-down

One more thing. Weight is relative. When I was young I carried 50 lb packs up high mountains. Today I get by with 26 lbs on a week trip. So opinion is just opinion. In my opinion you should be able to get by with a 2.2 lb (1 kilo) bag for three seasons easily. Liners to sleeping bags add a lot of weight because you are doubling the
"shell" or fabric part. Better to wear light down jacket to bed if you are cold (and long johns?) ....good luck.

I tried that this past May in northern Colorado. It was around 50 F. I had an Alps Razor liner + a space blanket + my poncho on top of that + wearing all my clothes. I was in a bivy. Shivered all night.

Much better to test your liner by itself on a car camping trip first. Just kick off your regular sleeping bag in the middle of the night, check the temperature, and see if you're comfortable.

The LaFuma you mentioned is actually 2.2 lbs. Not 1.2 pounds?

agree with other posters; impossible to respond without knowing where you are hiking. I have Colorado high peaks and Death Valley under my belt. Very different answers.

In VA/WV where I am currently, I have a Marmot 40 degree down bag that is super light, a few ounces, and compresses to next to nothing, that is good most of the year. Add a fleece liner and I'm good to about 20 degrees or lower if I wear my clothes. I sleep hot. So....where you are and how you sleep (hot or cold) has everything to do with it....

I just bought a 1lb 5oz Vaude Featherlight 200 for just over $100 & can't wait to use it

Not as well as it should.

(I have one.)