UKH

Hi All, 

Has anyone got any real-world experience with this sleeping bag liner, or the standard S2S thermolite reactor liner? I’m sceptical of the +11oC claim, but do you think it adds significant warmth? Also, I’m 5’9” - is it long enough to easily cover my shoulders? 
Thanks in anticipation for your wisdom and advice!

Definitely long enough, I have one.

Like bollocks does it add 11 degrees to a sleeping bag's rating, I'd say closer to 3 or 4 degrees.

If I hadn't left my sleeping bag at home for a hut weekend in the lakes and I'd been able to find another liner for cheaper I wouldn't have bought it, definitely not worth the £50 it cost at the time.

Insulation is all about thickness (bit of a simplification, but ultimately its how thick of a layer of air, the best insulator, something can something trap).  Now consider the thickness of the liner vs the sleeping bag... sleeping bag will do all the insulation.  Also consider the weight per thickness... again, sleeping bag is the winner.

Point is, liners are really just good for keeping the bag clean (not withstanding the benefits of vapour barrier liners, both for keeping the loft on longer trips, and also for reducing evaporative heat loss), and this is where a thin silk liner is best.  Although I prefer to wear merino or synthetic base layers for the purpose as its more comfortable and I use them in the day anyway.

I remember buying a fleece jacket from ME and it had a label on it stating it was as warm as wearing 12 woolly jumpers! My arse was it as warm as 12 woolly jumpers.

I thought about getting a S2S thermolite reactor but I was put off by the warmth to weight not being that great, which is a shame given their sparc sleeping bags are so insanely good.

 I find it hard to believe a fleece sleeping bag liner can increase 11C, even 2 if layers of fleece.

I did buy an omm core sleeping bag liner which probably adds 4c? to your bag (quoted as 0.7 tog dry or 0.4 tog when a bit wet) and is very very small and light, however it is also very very short. I'm 5' 10" (1.78m) and I find on the front it comes just below the nipples. I think it's supposed to be used in conjunction with an insulating jacket?

If you need a lot of extra warmth I'm afraid you probably need a warmer sleeping bag. Liners won't have anywhere near the same warmth to weight as a good bag. If you need an extra 11c you should get a thin liner like Rab silk neutrino sleeping bag liner, to help keep the sleeping bag clean, and put it inside a better bag, or consider wearing a synthetic "down" jacket to sleep. Sorry...

Hi All, thanks for the sage advice.

I've got one, I bought it for a trip to Alaska. It's a well designed liner, I like it and I've got my moneys worth over the years but the 11 degrees is total rubbish. A couple of degrees max. Saying that I dont think you would get a warmer liner for the weight.

I'm 5.10 and can get proper snuggled inside

agree with others warmth very overstated. 

They are wider/roomier than other liners I've used and therefore in many situations more comfortable but more bulky. The hood is smaller than some I have used. 

I think a good product overall, I value not being constrained but a different perspective. 

Glad that I have read this thread, as I too have my eye on the thermolite compact plus, for winter wild camping in the Lakes. May still go ahead, but I too was suspicious of the 11 degrees claim. How do manufacturers get away with their ridiculous claims for temperature ratings?