 Walter Villa would claim double world championships in the 250cc and 350cc classes for Harley-Davidson fighting off a strong challenge from defending champion, Johnny Cecotto in the larger class.Barry Sheene came to the fore with a dominating championship season in the 500cc division, finishing ahead of his Suzuki teammate Teuvo Länsivuori.Newcomer Marco Lucchinelli impressed as well on a Suzuki but injuries curtailed his performance.