It happened at an address on Firs Drive between 10pm and midnight on 19 August 2020.
It is believed the motorcycles were taken and ridden away from the address and headed towards the Leeds area.
The motorcycles had the number plates AV52KWS and WX56EKY, but these are likely to have been changed since.
The picture attached is of the 56-plate bike. The other bike is described as having the front right fairing being damaged and has had a messy fiberglass weld running through it and has a rear left seat fairing cracked as well.
We are requesting the public’s assistance to help establish the full circumstances surrounding the incident.
In particular, we are appealing for information about a Ford Focus seen in the area around the time and any sightings or adverts of the bikes for sale.
The owner of the bikes is offering a substantial cash reward for information given to the police which results in the safe return of both bikes
Anyone with information that could assist the investigation should contact North Yorkshire Police on 101, select option 2, and ask for James Skaith. You can also email James.Skaith@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 12200144624.