Loft of WM Summerlite

I bought a used Summerlite off Ebay a few months ago. I'll see if I can get some pictures tonight, but I measured it when I got it and it had the manufacturer stated 4" loft.

Mine is new with tags. I'll have to measure the loft (do you count bottom and top?), but it doesn't seem that great. Perhaps it has to fluff back up after being in a box for a week.

Sleeping bag loft is measured counting both top and bottom layers where a quilt is only top layer since they have no bottom.

You should definitely leave it a few hours to loft up before measuring. You can also do a bit of shaking/fluffing to get some air into it.

I'd be interested in seeing some pics of your bag if you think it might be underfilled.

Dave,

I forgot about this last night. I took the bag out of its cotton storage sack and laid it out for 20 minutes or so this morning. I measured about 3.5″ loft on average. Some spots were closer to 4″, some closer to 3″. I’ll lay it out again tonight for a longer period.

When I was researching bags, a summerlite owner on had this to say regarding his summerlite:

Just a quick note from a summerlite user. Someone mentioned the Montbell bag having areas of thin loft (where there is not any down between the two layers of fabric). In fact, I’ve noticed this with my summerlite before. The continuous baffles permit down migration, and the down tends to migrate down from on top of my body to the sides of my body if I don’t take a minute the fluff the bag up and shake the down to the top side (which is pointless anyway because I’m a side sleeper and will roll with the sleeping bag at night). I think this is just what happens when you build a down bag with such thin loft to begin with because the warmer WM bags I’ve used have not had this problem. All the more reason to go with a 40 degree Climashield quilt for summer use and a 20 degree down bag for 3 season use, but that’s just me.

That said, I’ve only had cold spots when parts of my sleeping bag have gotten wet. Even though it seems it, I wouldn’t say that my summerlite is truly underfilled because with underfilled bags you’ll have cold spots appearing in random places during the night (trust me, I’ve been there, done that, and have gotten fed up with a certain brand to a sleeping bag I bought promising to be good to 0 degrees but turning out to be so underfilled, cold air seeped in through gaps in the down fill at 30 degrees)–this has never happened to me with the summerlite, though.

In other words, on a the amount of down in a 32* bag may just be spread so thin sometimes that it doesn’t consistently have the promised 4″ of loft.

I can say that I did use my Summerlite for 2 nights in the low 40s (predicted) and had to unzip and quilt it because it was too warm otherwise.

The advertised loft for the summerlite is 9.5cm according to their metric specs. When you convert this to inches this comes to 3.75 inches. I guess that they just round it to the nearest half an inch (4 inches) when quoting in inches. If it was actually 4 inches measured, then it would convert to 10cm almost exactly and there would be no reason for them to call it 9.5cm.

So you shouldn't be surprised if your bag doesn't actually have a full 4 inches of loft. Should be at least 3.5 inches on average though.

Sorry if this is too offtopic, but this prompted me to go to Hermits Hut to see if they had an Summerlites in stock, since they do the free overfill. They don't list it as a option though. Is this bag available with overfill?

It is available with overfill as a special order. You might need to contact Hermits Hut and see if they can do it. Others have previously got their summerlites with overfill, but I'm not sure whether it was from hermit's hut or not.

Western Mountaineering will do overfill as a special order on new purchases. The dealer has to order it that way for this to happen. WM doesn't deal with customers directly except for warrenty issues.