First, let's define a bicycle. According to MCL 257.4, a bicycle means a device propelled byhuman power upon which a person may ride, having either 2 or 3 wheels in a tandem or tricycle arrangement, all of which are over 14 inches in diameter. This is not a vehicle with a motor. Therefore, we are not even discussing MCL 750.227d, which specificially deals with transporting or possessing a firearm in or upon a motor vehicle or self-propelled vehicle designed for land travel.
Second, I looked to find what the legislature meant by a "self-propelled vehicle". Initially, I thought of self as being individual. However, the statutes did not provide me with any clear definition of what was meant by self-propelled. So, I turned to case law, which is where the courts interpret the statutes. I first looked at People v Boscaglia, 357 NW2d 648 (Mich 1984), where the court said that a motor vehicle means every vehicle which is self-propelled and every vehicle is propelled by electric power from overhead trolley wires but not operated upon rails (citing MCL 257.33). So, alright we are looking at automobiles, trolley cars operating on overhead wires, but not trolley cars on tracks, not the People Mover since it is on a rail and not trains. Still no clue as to what a "self-propelled vehicle" is or is not. Then later in the case, the court states that a motor vehicle is an automobile, automobile truck, automobile wagon, motorcycle, or any other self-propelled vehicle designed for running on land but not on rails. Later, the court said the body of an automobile is not a self-propelled vehicle within the meaning of the statute. So there is a little more clarity on motor vehicle and what it is and is not, but not on self-propelled.
Then I looked at People v Jackson, Mich App 2012, unpublished. This case involved a rifle partially-covered by a blanket on the back seat of a car parked next to a vacant house in an alley. I looked at the case to see if it explained the self-propelled, but I learned a good tidbit to pass along. And I will at the end.
My Golden Nuggest from People v Jackson is this:
So long as evidence is in plain view in a vehicle, it may be seized without a warrant so long as police "are lawfully in a position from which they view the item, and . . . the item's incriminating character is immediately apparent." (cited from People v Champion, 452 Mich 92, 1996)
If, however, the police lack probable cause to believe theobject in plain view is contraband without conducting some further search of the object - i.e., if its incriminating character [is not] immediately apparent - the plain-view doctrine cannot justify its seizure. (from Minnesota v Dickerson, 508 US 366).
Next I did what the Justices will do first when the plain meaning of a statute is not clear, I consulted a dictionary. In Random House Webster's College Dictionary, "self-propelled" is defined as being "propelled by its own engine, motor, or the like." Therefore, after reading this definition, there is no way a bicycle can be a self-propelled vehicle if it is human powered. Therefore, MCL 750.227d would not apply and I could open carry on the bicycle and not risk being found to conceal carry. Although, if I put a small engine on the same bicycle, I have changed its characteristics and classification and would be found to be violating MCL 750.227d for open carrying while riding that same bicycle now equipped with the small engine.
So, yes. If the individual can legally possess the firearm, then he can legally oc while riding his bicycle.