Boulders, rivers and sheer rock — and one foot down costs you. These are the trials bikes that changed the sport. From a Spanish two-stroke that humbled the British heavyweights to the four-stroke nobody thought could win, we count down five machines that climbed the impossible. Which of these machines would you trust... on the edge of a cliff? Tell us in the comments 👇 Follow One Lung Racing for more machines the world tried to forget. Footage credits for every clip are shown on-screen throughout the video. #TrialsBike #ScottishSixDays #SammyMiller #BultacoSherpa #OssaMAR #MickAndrews #MontesaCota #ObservedTrials #OneLungRacing #MotorcycleHistory