What I remember is a guy and girls riding bike in the mountains, they end up starting trouble with a biker gang. Then the boy sees a girl wondering on an island, she's a ghost, and I think he had promised her something once so he must complete his promise to her. It's somewhat old, and I think this plot was the series' ova.
Could this be Idaten Jump? The story of a boy and his two friends (boy and a girl) riding his mountain bike and comes across Team Shark Tooth when they get sent to another world and they have to win races to return home.