Jan Gerrit Klok
I was amazed to witness how fast cars and buildings
shoot by while I seem to move effortlessly in slow motion.

But really what makes skating exciting is the _feeling_ of making the
motions more than the speed. Otherwise on pavement I'd just ride my bicycle.
On ice and pavement and indoor rinks, I think the majority of skaters aren't
much interested in speed, focused more on feeling and showing off cool
moves. Even on snow, classic double-poling can make the scenery shoot by
plenty fast enough for me, but I just don't like the feeling of my head
going up and down so much as it does in double-poling. And I spend lots of
my time on groomed snow skating up hills where I'm moving fairly slowly --
but still enjoying the magic of skating.

skating is faster than classic even for climbing up fairly steep hills.

Where was this difference measured?

Measuring it could get tricky because it's not even true that skating is
always faster. There's lots of different steepnesses of hills and lots of
different snow conditions. Actually for most of the hills and snow I ski on
the majority of my skiing days (which are on ungroomed snow), skating is not
very effective. So more important than measuring is to work out for yourself
what's appropriate for you in each situation.

For me the really convincing part was an unofficial uphill rollerskiing
"fun" race held some years in October to the top of a mountain which has
lots of sustained steep-ish climbing. Back then I figured the advantage of
skating was in the long glide, and there wasn't much glide up steep hills.
So I tried to be really clever by using Combi rollerskis, so I could do
Classic up the steep sections and then skate this one flat section in the
middle. The result that my time was completely inferior to this guy who
skated the whole thing. And he did not even carry any poles, just swung his
arms from side to side.

Later I read an article in a scientific book about cross-country skiing
which said that for skating up hills, over 50% of the power must come from
poling. Too bad the author wasn't at the race that day.

Would this be thanks to full glide wax jobs vs the grip pocket on classis
skis?

I think skating can be faster than classic for climbing up (many)
groomed-track hills, because skating uses propulsive forces in full 3
dimensions, so advanced racers discover clever tricks to engage more muscles
than 2-dimensional Classic. The classic ski design has more gliding
friction, but skating also has inherent inefficiency losses -- in the
physics of transforming sideways push-forces into forward work.

I think expert racers can engage more muscle mass in skating than classic,
by clever use of sideways moves. The energy from those additional moves is
not transmitted as effectively as classic (because of losses in the
directional transformation), but it still comes out as a net gain (in many
situations).

The physics of the interactions of all the different moves in skating are so
complicated, it's not an obvious result or something that a scientist should
have been able to predict. It's just the sign of the result happens to come
out from adding up a whole bunch of pluses and minuses (except when it's
different).

Ken