Two PCSOs saw the bike and its rider on Snapethorpe Road in Lupset while searching for a nuisance quad biker.
However, they came across the pedal cycle that had been modified with a small engine.
It was seized because the male biker had no licence, there was also no registration mark on the vehicle, tax or MOT.
The police said: "The vehicle was surrendered at the roadside by the owner whose details will be forwarded for reporting for the offences.
"The vehicle, which was not safe, will be unclaimed and destroyed."