Current primary data sources on mechanisms of Victorian bicycle crashes lack sufficient detail to draw clear conclusions on crash causation. Nor are these data adequate to link specific crash mechanisms to characteristic injury outcomes. The Monash Alfred Cycle Crash Study (MACCS) aimed to redress these data deficiencies through piloting an in-depth crash investigation study focused on cyclists. In-depth data were collected from 158 patients presenting to The Alfred and Sandringham Hospital Emergency Departments who were riders of bicycles involved in a crash. Information collected covered pre-crash factors pertaining to environment and cyclist/driver behaviour, crash mechanism, and injury outcomes from hospital records. Analyses of these data provide insight on crash causation and associated injury burdens which can inform the development, prioritisation and targeting of effective countermeasures.