Manufacturers started to experiment with more exotic composites and metals, like fiberglass and aluminium, but the common skateboards were made of maple plywood. The skateboarders took advantage of the improved handling of their skateboards and started inventing new tricks. Skateboarders, most notably Ty Page, Bruce Logan, Bobby Piercy, Kevin Reed, and the Z-Boys started to skate the vertical walls of swimming pools that were left empty in the 1976 California drought. This started the "vert" trend in skateboarding. With increased control, vert skaters could skate faster and perform more dangerous tricks, such as slash grinds and frontside/backside airs. This caused liability concerns and increased insurance costs to skatepark owners, and the development (first by Norcon, then more successfully by Rector) of improved knee pads that had a hard sliding cap and strong strapping proved to be too-little-too-late. During this era, the "freestyle" movement in skateboarding began to splinter off and develop into a much more specialized discipline, characterized by the development of a wide assortment of flat-ground tricks.
Freestyle skating remained healthy throughout this period, with pioneers such as Rodney Mullen inventing many of the basic tricks that would become the foundation of modern street skating, such as the "Impossible" and the "kickflip". The influence that freestyle exerted upon street skating became apparent during the mid-1980s; however, street skating was still performed on wide vert boards with short noses, slide rails, and large soft wheels. In response to the tensions created by this confluence of skateboarding "genres", a rapid evolution occurred in the late 1980s to accommodate the street skater. Since few skateparks were available to skaters at this time, street skating pushed skaters to seek out shopping centers and public and private property as their "spot" to skate. (Public opposition, in which businesses, governments, and property owners have banned skateboarding on properties under their jurisdiction or ownership, would progressively intensify over the following decades.)  By 1992, only a small fraction of skateboarders continuing to take part in a highly technical version of street skating, combined with the decline of vert skating, produced a sport that lacked the mainstream appeal to attract new skaters. 2b1af7f3a8