body mapped insulation (jackets). thoughts?

Here’s SectionHiker’s take:

https://sectionhiker.com/outdoor-research-acetylene-jacket-review/

https://sectionhiker.com/ll-bean-primaloft-superlight-jacket/

As a former Nordic patroller and XC racer I can see the benefits of the thin back and arms of these two jackets. Often at the end of a cold day of skiing I would come in with frost on my patrol jacket shell. The frost would be mostly over my shoulders and back and I’d have a wet waist where my 1st aid patrol fanny pack rode.

If I’m moving, I’d prefer straight fleece, or fleece and a wind breaker. But that’s just me…I use the puffy jacket for sitting around at camp.

Just to be clear.  The idea I am talking about isn’t limited to something resembling a puffy.  For example the OR Centrifuge is more of a fleece/fleece+softshell if I understand correctly.  And the OR Deviator also doesn’t really seem to fall into the puffy category given that the front is made of Alpha.  Basically my curiosity relates to simply having a substantial level of asymmetry to a jacket’s insulating properties.

i have a few body mapped jackets and pants and have found them to be hit or miss; really depends on materials, construction, and intended use. different amounts of insulation between front/back but all nylon cover…limited value. different between torso and sleeves/hood…more useful. bare fleece panels…much better. breathable panels under the arms and at the cuffs/hem usually make them more comfortable, if not for the air movement then for the stretch and tucking into pants/gloves.

the OR Centrifuge is somewhat specialized, but super useful for me. i sweat a lot, and more on my back than anywhere else, so thought i’d try a full fleece back. also really like the fleece mouth cover. took a chance on it and i love it (got it for about 1/2 on amazon, not sure i’d pay retail). i bought it for winter running (along with the pants) and cold weather cycling…fantastic for both. also tried for snowshoeing, hiking, and climbing with a pack or vest…definitely more comfortable without the extra nylon back there.

be careful when picking a jacket like this…i made a few mistakes before i found the Centrifuge. specifically: down synthetic insulation on the front was too warm for a fleece back…i prefer the full fleece jacket with just nylon on the front; nylon on the top of the sleeves is a must for me to keep my arms warm enough with higher winds or speed; and nylon on the hood for wind/precip.

a few other things I really like about the Centrifuge that are different from similar jackets are the fleece mouth cover for really cold conditions or blowing snow and the out of the way thumb loops.

I’ve owned a couple of hybrid, zoned insulation design jackets and I personally find them to be very useful on colder days, especially when layering under a softshell.

Whatever design you opt for, I’d recommend ensuring the back section is as open as possible with fleece/merino being the primary material from your waist up to the shoulder blades. The back covers a large surface area and is usually under a pack, so having some type of synthetic insulation + liner + pack creates a massive, sweaty hotspot for me that outpaced the underarms and flanks ability to vent.

I haven’t thought much about it, but have found that Nordic ski clothing that is warmer and more wind-resistant in front and more breathable in back does function better.

Living in the sub-arctic and working in the arctic causes me to focus on the face and hands the most.  Minimizing conductive and convective heat losses while maintaining forward vision has been a struggle for thousands of years and I prefer a tunnel hood (to a sun-burst parka hood or face mask).

In addition to traditional parka patterns, I like the Native philosophy of “never sweat”.  So while placing insulation where it does the most good is a win, I’m more interested in being able to REMOVE insulation or open zippers and vent to cool off when needed.  Carhartt’s insulated coveralls aren’t UL by any means.  But they have full-length zippers. I’ve been mushing a dog team at 1 am on a January night at -10F with the zippers open from shin to belly (but with fleece undies to protect the tender bits).  While wrestling a sled and running up the hills, the coverage in front of me blocks the wind and the open zips dumps most of the heat and humid air.  Then being able to quickly zip up when we stop exercising or if the wind comes up is VERY helpful.

Thanks for the thoughts.  Seems like people find the front/back asymmetry most useful for activities where you have a large dynamic range of effort.  Backpacking should fit that requirement, and even dayhiking should as well.  I don’t really _need_ any more jackets/clothing, but I’m tempted to try out one of these garments.  But in an effort to curtail my spending I opted to just sew a vest with uncalendered ripstop on the front and lightweight mesh on the back (2 oz total).  I should be able to wear it over a fleece to get the desired effect.  It is warm in the front range now, but towards Fall I can test it out.  If having the extra wind shell on the front torso works for me then I’ll drop the $$$ on a a fancy garment like the deviator. If it doesn’t make a difference the I’ll save the cash.  Cheers.

And there are cheap and free ways to try the concept.  While I was at Berkeley, a grad student stayed late after dinner, it got cold, and he had to bicycle a long ways home.  He asked for a used newspaper, separated the sheets, crumbled them up, and stuffed them under his wind shell on his front.  An instant, free, insulated parka!

Similarly, you could insert or safety-pin a small fleece blanket and/or a chunk of tarp/plastic sheeting in different places and see how you like it.

Speaking of newspapers and cycling, it has been a tradition for more than a century — and remains so today, after all the technical development in garments — for cyclists in the Tour de France to grab a handful of newspapers and stuff them into their jerseys at the top of alpine passes to provide a key bit of core insulation on the long, cool descents.

Cycling vests with a wind-resistant front panel and mesh back have been standard fare for a long time. I have one in the closet that I use quite a bit in cooler/cold weather… I’ve had it for about 25 years! As David suggests, I have also used a plastic grocery bag for those times when I forgot to bring the vest.

For backpacking, I have found that my lower back is going to get damp no matter what I do. However the dampness can be mitigated by regulating the temperature of the rest of the body by using the minimum number of layers necessary for the exercise level and by venting and by removing hat/gloves or pulling up sleeves to expose wrists/forearms. I find big pit zips and leg side zips for shell jackets and pants to be vital.

IME it is impossible to find something that is going to be comfortable all day at all activity levels that does not involve managing layers and venting. But with a light polyester base, light (100 wt fleece or R1 grid) layer and shell jacket with pit zips, I can remain quite comfortable in very cold weather all day. When stopping, throw on a puffy over everything and remain warm. This is why a generously sized, belay-style puffy that fits over all other layers is essential.