I have distinct opinions on the use of double boots in cold weather and winter climbing. But this winter with even more of a chance of a cold injury myself I am beginning to wonder if there aren't more factors involved that keep your feet warm and in good shape than I had previously suspected.
I'll get to that theory in an upcoming blog. For now I'll stick to what I do know about in cold weather climbing. Think multiple days out in winter in the Rockies or Alps, high on Denali or early spring in the Ruth Gorge. Places that most experienced climbers will prefer a double boot.
To that end I wanted to give some more details so it is easier to make a good choice on your own foot wear and may be give you some options you might not been aware of previously.
Here is a quick review of most of the plastic versions:
The other boots I mention, Baruntes, Spantik, and Phantom 6000 can be found by a search here or google by a "cold thistle spantik" search for example. Just add the model you want more info on in place of "Spantik". The Oly Mons info while new is long over due here.
All that info can now be found by a simple search.
Boots.. one boot .. (size 45)
Two of the lightest boots available and suitable for winter mountaineering in milder conditions:
La Sportiva Trango Evo Extreme GTX 2#3oz (35oz) / 992g
Scarpa Phantom Ultra new 2010 model 2#3.5oz (35.5oz) / 1006g
Both of these "1000g" boots are a real pleasure to climb in because of their over all weight and sensitivity while climbing on steep ice or rock.
The lightest plastic double boot is a Scarpa Omega. Which is lighter than many of the current state of the art single boots.
Omega 1110g or 39 oz. total 2# 7 oz
Omega's Intuition inner boot 140g
La Sportiva Batura 1st gen. 2#7oz / 1106g
La Sportiva Batura 2nd gen. 2#9oz / 1170g
La Sportiva Batura 2, 3rd gen 2#3oz /1000g
Scarpa Phantom Guide new 2010 model 2#7.5oz / 1120g
There are really only 4 boots that I recommend for really cold climbing. La Sportiva dominates this catagory for good reason, it offers three great boots with differing and distinct features. But no matter how good the boots are if they don't fit you well, stop, drop the boot and move on. I use a Baruntse inner boot that has been heat molded to my feet in the Baruntse, Spantik and Oly Mons. I've tried to do the same with a Intuition Denali liner with less successful results. The intuition liner stiffens the ankle flex in all the boots more than I would like and is a true VBL. YMMV but you need to know there are options to the original inner boots. I like the custom fit, added warmth and easy lacing system of the Baruntse linner. But just as important is the over all weight.
In the upper Midi station
The size 45 La Sportiva Spantik with a Baruntse liner comes in at 2# 12oz / 1247g. In that form the Spantik is a warmer boot with more support than the Scarpa 6000 with only a 2oz total weight penalty per boot. 4oz per pair in a 45 or 2oz per boot.
On the Montenver's train
The Scarpa Phantom 6000 was new in 2010. A full dbl boot with intergal gaiter @ 1190g / 2# 10oz is the over all winner in the weight catagory. It equals the Spantik and Baruntse in warmth right out of the box. Only the "custom" Spantik with a Baruntse liner is warmer as a technical boot of similar volume imo
The advantage to the 6000 at that point? The 6000 is slightly more flexible in the sole and ankle and the 6000's integral gaiter is always a benefit in cold snowy weather. And it is still the lightest of the "very warm doubles" but still not at the weight of the Scarpa Omega. Missing by 6oz per pair in a size 45. But the 6000 (or any of the better doubles) is a gazzillion times easier to lace up!
1/2 dozen of one 6 or the other between the two. I like the extra support and volume of the Spantik a majority of time when I need that warm of boot. But I have the option of the Baruntse liner to keep the weight down as well.
Oly Mons 3# 5oz / 1500g
Oly Mons w/Baruntse liner 3# 1oz / 1390
La Sportiva Spantik 3#.05oz / 1362g
La Sportiva Spantik with a Baruntse liner 2# 12oz / 1247g
Scarpa Phantom 6000 with intergal gaiter @ 2# 10oz / 1190g
La Sportiva Baruntse 3#2.5oz / 1503g
La Sportiva Baruntse w/inner and lwt sole 2# 15.5oz
More here on how to slightly improve the Baruntse:
The Baruntse geenrally gets short shrift when the discussion gets to the best doubles. I noticed recently a interesting article on Alaskan climbing, where the author noted the use of full down suits on Denali and no mention of the Baruntse...just the 6000 and the Spantik. Seems to be the only quality double boots the author was aware of. Down suits on the other hand haven't been used on Denali by anyone able to buy a clue in a long while :)
Denali is cold in early May but not that cold!