In the first incident, a motorbike was taken from an address on St Georges Road at around 02:30am before being abandoned a short distance away.
The suspects, believed to be four males, are then believed to have attended an address on South Park Road, Harrogate at 03:20am where a rare, Aprilia RS250 Mk2 was stolen.
The motorbike has distinctive bubbling to the surface of the fuel tank which should distinguish it from similar bikes.
Officers are appealing to anyone in the area including residents with CCTV or doorbell video, and passing motorists with dashcam footage. to check their devices in case the suspects have been captured on camera.
In particular, they are appealing to anyone who saw four males acting suspiciously at this time.
Anyone with information or footage that could assist the investigation should contact North Yorkshire Police on 101, select option 2, and ask for PC Dean Barrett, collar number 1573.
You can also email Dean.Barrett@northyorkshire.pnn.police.uk
If you wish to remain anonymous, you can pass information to Crimestoppers on 0800 555 111.
Please quote the North Yorkshire Police reference number 12210185790.