Combination grind

Back in the days when all serious skaters did both figures and freestyle, everyone had two pairs of skates, one for figures (called “patch skates”) and one for freestyle. But having two pairs wasn’t a requirement to begin skating. Everyone started out with only one pair. A second pair wasn’t considered necessary until second test or thereabouts. Today, experienced freestylists getting started with figures may find them very difficult. For one thing, they leave too many flats to pass any test. Why did it work back then? I think a big part of the answer is the way skates were sharpened. Back then, skaters with only one pair of skates used combination grind, which seems to have been forgotten.

Flats occur when both edges of the blade touch the ice. When you get the light to hit the ice at the correct angle, the tracings left look like two lines separated by the width of the blade. This happens even if you are skating on a curve! In contrast, when you’re on an edge, your blade leaves only a single line. Whether your skate leaves a single line or a double line depends on how far to the side you lean as you glide: you have to lean far enough to get the other edge off the ice. How far you have to lean is determined by the centripetal force as you go along a curve, which is a function of your velocity. Having a flatter hollow on your blade means you don’t have to lean as far to get your other edge off the ice, enabling you to go slower on a single edge. Sid Broadbent has a good discussion of this in Skateology.

Today’s freestyle skates are typically sharpened to a fairly deep radius of hollow. 1/2″ is quite common, and some skaters go as deep as 3/8″. For figures, you want a much flatter hollow. 1″ is the usual starting point; they went up from there. A shallow hollow digs into the ice less, helping you avoid flats and glide for longer from a single push. It also makes turns easier. But it means you have to skate correctly: if you’re not right on the edge, a patch sharpening will skid when a freestyle hollow would feel secure.

With such a big discrepancy, it’s no wonder freestyle skates don’t work well for figures. I think people have forgotten about combination grind. Skaters who did figures and freestyle with a single pair of skates typically used an in-between hollow, something like 3/4″ or 5/8″. This worked adequately for the lower levels of both disciplines. But once they became more skilled, these skaters needed a deeper hollow for control in freestyle and a shallower hollow for good figures. Hence the two pairs of skates.

The outcome is: If you are trying to do figures and find that you have way too many flats, try asking for a flatter hollow next time you get your skates sharpened. It should help you get rid of flats, but will feel very strange and possibly mess up your non-figure skating.

The two other main differences between patch and freestyle skates are:

  • Soft boots allow the ankle mobility necessary for fine edge control. Back when everyone did figures, boots were much less stiff. Skaters didn’t need super-stiff boots because they weren’t doing all the big jumps seen in competition today. Even beginner boots are awfully stiff for figures today.
  • Skaters often shaved off the bottom of the toe pick on their patch skates to avoid extraneous marks on turns. Blades designed for figures came with this modification out of the box. At the lowest levels, this isn’t necessary.


Sidney Broadbent. 1997. Skateology: A Technical Manual for Skaters Regarding Skates, Skating Fundamentals, Skate Sharpening. Revised ed. Littleton, CO: ICEskate Conditioning Equipment.