BARRIE, Ont. - Police in Barrie, Ont., say a man who crashed his bike is facing charges after a woman tried to help him and was sexually assaulted.

Investigators say a 24-year-old woman was walking on a trail Thursday afternoon when a male cyclist rode by on a bicycle and then crashed into a bush.

Police say the woman -- fearing the cyclist was suffering from heat or sun stroke because of his erratic behaviour -- offered to go to a nearby store to get him some water.

It's alleged the man then became belligerent and grabbed at the woman, who managed to get away and call police.

Police say a 26-year-old Barrie man is charged with one count of sexual assault and an investigation continues into whether alcohol, drugs or medical conditions played a role in his behaviour.