My first introduction to skiing was on an ancient pair of roller-skis with very low ground clearance; every time I went over a bump, the skis would ground and I would land on my face, which accounts for my present good looks. I would then have to bash the skis on the ground for a while to get them to run straight again. I do not know how much good this did me, but I did do quite a few sessions before I got onto snow, and did pretty well in my first race, given that it was my third day on snow.
I got out of the habit of roller-skiing for a while, just doing the occasional session, until I decided in 1997 that it was going to be a big part of my training. At that time I did not enjoy roller-skiing because I was concerned about falling and my technique was not good. I decided that the best way to motivate myself to learn to do it properly was to enter some roller-ski races.
My first race was the 30km at Eelmoor in June 1997. A flattish easy course, and I imagined that I would do fairly well. I was flabberghasted when I was repeatedly lapped by old guys, kids, fat blokes etc etc. I had no idea what was wrong, and it was not until I tried a pair of skis from one of the others afterwards that I realised that there is a great difference between the slow wheels that are good for training and the fastest possible wheels that one would use for racing. I bought a second-hand pair of Marwe racers from Jeremy Knight, who was at that time way ahead of any other Brit on roller-skis, and got a lot closer at the next race.
By then I had done enough roller-skiing that I could balance adequately and execute all the techniques (in skating it was a long while before I got a pair of classics), so the races had fulfilled that motivational function. But they are such fun that I have carried on doing them.
I am fully convinced of the value of roller-skiing as the best possible off-snow training. The physical demands are more or less identical to those of skiing, and the techniques are close enough that one can make significant technical improvements in the course of a Summers roller-skiing. For example, in the Summer of 1997 I used roller-skiing to learn to V3 on both sides (previously I had used it only on one side), and now ski completely ambidextrously. In 1998 I made significant changes to my skating technique, from the old-fashioned German biathlete style which I had reinvented for myself, to a Norwegian style. I have now moved to something in-between, again largely by roller-skiing.
Training: Marwe Skate 610 (with No.6 or No.7 wheels), which have big, narrow wheels (105x20mm), which makes them hard to balance. They are fairly slow (Marwe does several different wheel speeds), which I like and behave well on fast descents. I have been using them for years and love them. Everyone is now cottoning onto these, and they are now used by many German, Italian and Norwegian team members, and doubtless others. Quite hard to balance if you are not used to them, but well worth persevering with. Similar models are made by Swenor, Elpex, DMS, Pro-ski.
Marwe Classic (Ratcheted No. 6 wheel in front, No.7 behind): a good, reasonably well-behaved ski, although it tends to swim a little. Sometimes too fast - especially on a hot day and a smooth surface. I think I would probably prefer the Combi, which is shorter but has a dolly wheel attached to the front which guides the ski forward after the kick much like the tip of a classic (snow) ski. Slower wheels would be nice for Ruhpolding, as I tend to double-pole all the flat sections, while slower wheels would make me kick-double-pole.
Marwe Skate: like the Classic above, but shorter. In a skate roller-ski the tendency to swim is unacceptable, and I do not recommend these.
Nordic 2000 skate: these are astonishingly slow, and very hard work. They do not grip well in the wet. (They have brought out a new wheel which they say grips better, with the same rolling resistance). Good prices - around 200DM without bindings.
DMS skate: even slower than Nordic 2000, and very similar. The old (white) wheels slipped terribly in the wet, so they brought out a new (blue) wheel that supposedly is as slow and grips in the wet. Well, sorry, but it still slips, is faster, and wears out disgracefully fast. The roller-skis tend also not to run straight, and have to be tinkered with to make them safe. Reasonable prices.
Racing skate: Eagle Rabbit: because of their very narrow wheels and straight chassis these are quite wobbly when you are not used to them. They were the most popular model at the World Games in Sonthofen in 1999; apparently it is worth fiddling with the bearings to make them quicker, but I have not done this. It is definitely worth training a little on these before a race, as you cannot make them go fast if you wobble on them.
Racing classic: Eagle Road Trainer Classic with polyurethane wheels (both ratcheted). These work fine for an uphill race, but are not the kindest in descent.
General tips on roller-skis: