The break-in happened on Lisvane Avenue at around midnight on Sunday.
A PowaCyle Prague bike in black, minus the battery, was taken from the garden shed.
A North Yorkshire Police spokesman said: "We are conducting enquiries and are requesting the public’s assistance to help determine the full circumstances surrounding the incident.
"In particular, we are appealing for information about the stolen property in addition to the offender or offenders of the crime."
Anyone with information is asked to call 101, select option 2, and ask for Georgina Hanson.
If you wish to remain anonymous, you can pass information to Crimestoppers on 0800 555 111.
Please quote the North Yorkshire Police reference number 12170025152.