Back when all competitive skaters did both figures and freestyle, everyone who had reached a certain level had two pairs of skates, “patch skates” for figures and freestyle skates. The main difference was that freestyle skates have a larger toe pick and are sharpened to a smaller radius of hollow. Patch skates were often old, worn-out freestyle skates with the toe picks removed and blades sharpened to produce a much flatter hollow.
Dick Button, winner of the 1948 and 1952 Olympics, had a third pair. These skates were optimized for loops, figures based on circles with a diameter approximately equal to the skater’s height. Other circles were three times as large. Here’s what Dick had to say about using special skates for loops:
These figures are so much smaller than the larger, conventional eights that a different radius along the length of the blade enables one to sink lower into knee action going into the figure without digging sharply into the ice. I cut the bottom toe pick of these skates even further than those for other figures since there is no need for a toe in any loop while they can be very much in the way.Button (1955, p. 185-186)
Dick’s decision to use blades with a smaller rocker radius—meaning more curvature from end to end—is consistent with results obtained by Henry Vandervell in the previous century:
I have had very considerable experience of the effects of radii, viz., from 20 feet to 2 feet. The extreme I fix for combined skating is 9 feet, and for single figures of the epicycloid variety, such as loops, crosscuts, etc., is 3 feet. If, now, you average the two kinds you get to 6 feet for all-round purposes.Vandervell (1901, p. 24)
Today’s figure skating blades have rocker radii of seven or eight feet, rather more than you want for loops. No blades with smaller rocker radii are currently on the market.
Dick Button (1955). Dick Button on Skates. Englewood Cliffs, NJ: Prentice-Hall.
H. E. Vandervell (1901). The Figure Skate: A Research into the Form of Blade Best Adapted to Curvilinear Skating. London: Straker Brothers.