Loft is measured as fill power. That 800-or-so number you see
on the material tag? That’s the volume in cubic inches 1 oz. of the
material can fill in a test device. The higher the number, the better.
Here’s another tip: Primaloft supplies Northface with a synthetic material that has proven to be the insulative equivalent of
600 fill power goose down—another reason to choose synthetic
if it’s made of this material. Duck is the most common down
(limited to about 750 fill power) and Goose, which can reach
850+ down, has become extremely expensive. If you need 850+,
buy Goose down, if not, save a few bucks.
My favorite bags? My solo riding go-to bag for below 55° is
the REI Polar Pod (second from left in the above picture, and
I swear I don’t get a dime from REI for this). It’s a roomy 27°
synthetic bag that’s also easy on the budget. Typically sold for
between $80–$100, you’ll sometimes find them on sale for as
low as half a Benjamin. It packs large at 15 liters, though, and if
you’re two-up you may want to consider the backpacker’s Mountain Hardwear’s Lamina 35 (third from left) at one-half the size,
only 6 liters, but for roughly double the price. For backpacking,
less is more (expensive). If you’re riding and camping in temps
colder than this, you might want to trade for a snowmobile with
a few Huskies. Check out Marmot, Montbell, Feathered Friends,
and Western Mountaineering (far right in the picture) for the
hard-core stuff. Oh, and check out Mountain Hardwear’s Phantom 45 with a lower limit rating of 40° that, wait for it—weighs
under 20 oz. and packs down to 6" x 10" (approximately $270).
That covers the thermoregulation basics. Almost. Except for
that gravity issue again, where lying on all that aforementioned
insulation compresses it and renders it useless. Plus gravity has
a way of making that little stone or stick you’re lying on feel like
a boulder or a tree. Enter the sleeping pad. In fact, it’s so much a
necessity that some bags are designed in combination with them
and deemed sleeping “systems.”
You could opt for the inexpensive, somewhat insulative closed
cell pads, but at under an inch thick, they feel quite thin. Great for
youth, perhaps, but us pentagenarians need a lot more padding.
Next are the basic air pads that double as pool floats. They are
lightweight and perfect for warm camping. A few decades ago, a
couple of laid-off Boeing engineers came up with the self-inflating
pad by using enclosed spongy open-cell foam with good insulative
properties inside an air pad. They did well, as does the pad, which
is available in various thicknesses with corresponding warmth.
But the best of all worlds is the lighter-weight and small-
er-size air pad with added internal insulation. Pad insulation, the
reciprocal of conductivity, is rated with an R-value (resistance).
Yes—the same as you might see in construction (e.g. your house
attic insulation might be R- 30). An air pad can be rated as low
as 1, closed-cell foam 3. 5, self-inflating 4. 8, and the insulated
air pad 8. Consider, there will be eight times as much heat loss
over a very large area between the first and last types.
During the summer, I’ll use my trusty Thermarest NeoAir
( 2. 5" R- 2) and, in the winter, the wonderful Exped Downmat 9
DLX ( 3. 5" R- 8). In the picture from top to bottom, a closed- cell
pad, the NeoAir, a self- inflating pad, and the Downmat.
Here are a few tips for cold-weather sleeping: Eat. It’s no sur-
prise that heat and food are both measured in calories. In fact,
eating 1000 calories of food will heat one kilogram ( 2. 2 lbs.) of
your body’s moisture content 34°—mostly in the deep organs
like the liver, brain and heart. Wear full-length thermal under-
wear and socks and have a fleece ready. Be sure to get rid of any
excess internal fluids (euphemism) so your body won’t have to
maintain their temperature before you hop in the sack. Finally,
take a NOLS winter camping class. You may never find yourself
in extreme, life-threatening conditions, but if you do, you might
Finally, as an engineer with access to an IR camera, I just
couldn’t resist doing a little research. The bottom image is me
in my Travel Sack on top of the NeoAir on the ground at 46°
ambient. The top is in the Polar Pod and Downmat. A lot can be
discerned from these images but I think the most profound is the
warm temperature around the perimeter of my body and edges
of the NeoAir pad showing a lot of heat loss.
If you’re like most long-distance motorcycle campers, you’ve
dedicated a lot of the most precious resource you have—free
time—to enjoy a week or two riding and camping. To make the
most of it, prepare, get the right gear, and always get a good
night’s sleep to enjoy all of your riding wide-awake.
Sleeping pads are equally as important as sleeping bags and many
are sold together as “sleep systems.” The pads are given R values,
just like attic insulation. From top to bottom: A simple closed cell
pad (R- 3. 5 but thin without much cushion), the Thermarest NeoAir
( 2. 5" R- 2), a self-inflating type (R- 4. 8) and the Exped Downmat 9 DLX
insulated air pad ( 3. 5" R- 8).
Infrared images show the relative heat loss of my Polar Pod bag
with Exped Downmat pad at 46°F ambient (above) vs. the Travel
Sack with Thermarest NeoAir pad. The sleeping camper above is
warm and toasty inside and the one below may be shivering.