Over the years, I have a developed a pretty good personal layering system for ice climbing. My bottom half layers remain the same throughout the day, made up of my current favorite climbing pants and some sort of baselayer whose thickness depends on the weather. My top half usually consists of 4-6 layers, again depending on the temperature. These layers will be taken on and off at various stages throughout the day.
This winter, I have been testing out a couple new systems using current (or even future) season gear and am happy with them so far. One particular setup served me very well in Bozeman, where we went from standing around in "minus bajillion" temperatures to working up a sweat bushwacking up the side of a mountain through deep snow. Everyone has their own personal preference, but here is a look at what works for me.
1. Sports Bra: My top-half layering system always starts with either a synthetic sports bra from Moving Comfort or a wool sports bra from Smartwool (coming Spring 2013) for some added warmth.
2. Merino Wool Tank: I add a merino wool Siren Tank or Everyday Cami from Icebreaker as my first layer. The tank provides both extra warmth as well as temperature regulation in case I sweat on the approach. If I get overly sweaty on the approach (bad management on my part), I may just remove this tank once I get to the base of the climb, eliminating any wetness that will quickly chill me later. Many of my super heat producing friends do this as well. You could even bring a spare one in your pack to change into later.
3. Long Sleeve Base Layer: This layer could be either merino wool or synthetic, with the former giving you the benefit of anti-stink. If I am going on a long trip where I might need to wear the same base layer a few days in a row, I always go merino. In Bozeman, I was quite happy with my Patagonia Capilene 4 Expedition Weight base layer made from Polartec Power Dry High Efficiency fabric. The Capilene 4 is a quick drying, breathable, hooded base layer with high loft brushed fleece interior for extra warmth. For all but extreme cold approaches, I am usually stripped down to this layer.
4. Insulated Vest: If it's extra cold, I will throw on some sort of insulated vest over my base layer to add some core warmth on the approach as well as throughout the day. I have so far been impressed with the new Polartec Alpha insulation I wore the entire week in Bozeman. The insulation is not too heavy, breathes well, and really captures your warmth when you get moving.
5. Fleece Layer: In the past, I have worn hybrid layers that combine items 4 & 5, in both merino and synthetic, such as the Sherpa Mantra Jacket or Adidas Terrex Swift 3-in-1 Jacket. This season, I have instead been wearing the Patagonia Piton Hybrid Hoody over the Polartec Alpha vest, creating a layer I can easily remove as the day warms up or even wear as an outer layer in more moderate conditions. Made from a combination of Polartec Power Dry and DWR treated Polartec Wind Pro, this technical fleece makes the perfect versatile climbing layer. If you are looking for a good current season 4 & 5 combo layer, check out the Outdoor Research Lodestar Jacket. Again, this is down to personal preference and desired level of versatility.
6. Shell: I generally climb in a softshell, but if the weather is really windy, snowy, or freezing cold, I will throw on a hardshell. I wore the Patagonia Alpine Guide Jacket throughout the week in Bozeman. There is no hood on this softshell, but when the weather was bad enough, I replaced the Alpine Guide with my Marmot Nabu NeoShell hardshell jacket with hood anyway.
7. Belay Jacket: These vary for me depending on whether I am multi-pitch climbing in the backcountry or single pitch/ice cragging. For single pitch and ice cragging, I have been happy with the puffy and warm Montane Ice Guide Jacket. For multi-pitch climbing, I stuff the L.L. Bean Downtek water resistant down jacket in my small climbing pack to pull out at belay stations, as it packs down better and has a lower profile. One sub zero morning in Bozeman I even wore both of these jackets while we stood around.
So there you have it- my typical layering system for ice climbing. I would love to hear your thoughts and if you have a system that works better for you.