The warning comes after officers seized this bike in Conisbrough yesterday.
A spokesman for Doncaster West Neighbourhood Policing Team said: “This bike was seized in Conisbrough after being found being ridde illegally around Edlington and Conisbrough.
"If we find you riding illegally, there is a likelihood that your 'pride and joy' will be seized.
"Believe it or not, there are plenty of sites throughout South Yorkshire where you can enjoy this 'hobby' – if you don't believe us, Google it.
"If something's worth doing, then it's worth doing right.”
Police in South Yorkshire have launched a number of recent operations tackling off-road biking, particularly in the Conisbrough area, where riders have been destroying farmers’ fields on their machines.
Anyone wanting to report incidents can contact South Yorkshire Police on 101.