The 1980 April issue of Bicycle Motocross Action has Tinker Juarez on the cover. If you have heard that Tinker name in the last few years you probably follow the mountain bike scene. Tinker currently rides Marathon MTB rides (unless they steal his bike holding him at gunpoint) and used to be USA's hope in MTB cross country races riding for Cannondale for a long time.
As you can see, Tinker got his skills from racing BMX (Mongoose pro) and riding his motomag at the skateparks. Tinker was quoted in this issue as:
"The master of Vertical Surface; the Absolute Ruler of the Concrete Bowl; the King of the Skateparks."