Peter Clinch wrote
My backcountry touring typically uses more nordic flat technique.

In that case I can see how you'd think of "classic" rollerskis, which have a
clutch to prevent the rollerski from rolling backwards (sort of like the
effect of a climbing skin). But the Original Poster mentioned "telemark
turns", so I didn't think he was looking for that. (But then some "skate"
devices other than rollerskis do also have a clutch, so why not try using
those to train for flat touring?)

a lot of backcountry skiing is about covering
reasonably level ground in straight lines

If I know a pretty tour that's mostly flat and gentle, I prefer to wait
until a day when the snow is pretty firm, and then _skate_ most of it on
very-light skating skis. For a great article about ski skating in the
backcountry, see "Skating's Second Season -- backcountry skiing takes on a
new twist", by Mark Nadell, in
http://farwestnordic.org/Newsletters...cnews_2005.pdf
Even with some new snow, like 8 cm / 3 inches of fluffy powder -- if it's
over a firm base -- is fun skating on rolling terrain with light skating
skis.

For learning technique and neural control, the value of Classic rollerskis
is very debatable in the XC set-track skiing community (as Booker pointed
out).

For training endurance and speed of specific leg muscles for flat
backcountry skiing, Yes I can see value in Classic rollerskis -- but that
raises the question of:
? traditional roller skates ("quad" skates) versus
? Classic rollerskis

which I've never seen debated.

my friendly neighbourhood nordic instructor

My theory is that nordic instructors are unconsciously against inline skates
because they're afraid that if people found it how much easy fun they
could be having moving on their feet, the demand for techniques and
character-building tours of one-dimensional skiing on snow would drop.

Ken
_________________________________
Peter Clinch wrote
Ken Roberts wrote:

Why? How?
What is it about the physics or biomechanics of rollerskis that makes
them
more "specific" for backcountry skiing than inline skates?

Because you use a boot that flexes under the ball of your foot to
transfer power straight back, where blades will only allow you to kick
off at an angle to the line of the skate.

How many rollerskiers can make linked christie/parallel turns down a
hill
like a good inline skater?

How many rollerskiers can make a long glide on a single ski and change
between the inside and outside edges 8 times like I can on inline skates
(or
on a single backcountry snow ski going down a firm-snow slope).

And how many rollerbladers can use good straight ahead diagonal stride
to cover a lot of ground over the great majority of muscle use time
spent over a day?

Personally I use blades, but my friendly neighbourhood nordic instructor
and professional backcountry tour leader uses rollers in direct
preference because they're more like skis for the business ofbasically
covering ground. If you're in a steep up, steep down mode then I would
say they'd have little utility, but a lot of backcountry skiing is about
covering reasonably level ground in straight lines, which rollerskis can
help with better than blades.
My backcountry touring typically uses more nordic flat technique than
downhill with day's hut to hut in Norway typically involving single
figures of tricky turns, but double figures of kilometers following
tracks. YMMV.