The short skates with no toe stops and at least the breakdancing-like moves used in the film are associated with post-roller disco "jam skating." Both came onto the scene in the '80s. Roller disco skates had high-cut boots like figure skaters and had toe stops.
When Curtis gives X his new pair of skates, the packaging says "Sure Grip" but when he opens it you can clearly see the Riedell Orange "R" symbol on the heel of the skate. For one, the two skate brands do not match up, and also, the skate is a modern Riedell model not produced in the 70s.