A maverick underdog, a troubled depressive, a sporting hero and an autodidact engineer given to cannibalising bits of kitchen equipment for his self-built bicycles, Graeme Obree’s life is cinematic gold. This documentary follows a so-so biopic, The Flying Scotsman, covering his early life. Battle Mountain benefits from the fact it contains Obree’s own voice, rather than a fictionalised account of it. He’s compulsively honest – revealing his bipolar disorder, his long-closeted homosexuality and a nasty abscess that threatens his training – and remains endearingly enthusiastic, although we can occasionally glimpse a darkness through the cracks in his chipper persona. Twenty years after he broke his last world record, Obree is out of retirement and trying for one last title at the International Human Powered World championships taking place in Battle Mountain, Nevada. He is riding the Beastie, an arse-chafing torture machine crafted out of saucepans and old roller skates. Like the Beastie, this film never quite picks up speed, but it is certainly a more enjoyable ride.