In the very early years of motorcycles (1892) there was a 5 cylinder Millet rotary engined bicycle with the engine built into the rear wheel and a tricycle with the engine built into the front wheel.
These are mentioned in "The World of Motorcycles an illustrated encyclopedia" but not a great deal is said except the weight of the engines cylinders which were bolted directly to the rim of the wheel and rotated with it produced huge gyroscopic forces that made turning difficult.