The bikes were all stolen from outside Northbrook College on Broadwater Road between May 23 and May 25.
The suspect cut the locks with bolt cutters on each occasion and rode away on the stolen bicycle.
He is described as a slim white man in his early 30s with a dark goatee.
If you recognise this man or have any information that could assist the investigation, please contact police online or by dialling 101 and quoting serial 47220093960.