I was reminded of this when reading 80s movie about a genius boy who invents a force field to deflect football balls. This was a Disney TV movie I watched, somewhere between the mid 80s to the late 90s in the United States, possibly on cable television or broadcast. The protagonist was a bright, but lazy, kid who often got in trouble at school. He invents a contraption for his bicycle that, when he pushes the button, lets it jump high in the air (I think with a pneumatic hiss sound effect). I remember a scene where he demonstrates in a horse-jumping arena. He sells the device (or gets an advance on it?) and buys himself a bunch of things that a kid would think cool, but still finds himself unpopular. I think I remember a scene where his birthday party has a famous rock group playing at it, disco lights, and smoke machines, but no one shows up. At some point, later in the film, it becomes important for him to get from point A to point B really quickly, so he grabs an earlier prototype of the bike (I think this act voided his earlier contract, which I remember made me wonder how he was going to pay back all of the money he already spent) and rushed across town, using the device to let him make spectacular jumps. I want to say that there might have been a mild twist in that he realized that the device didn't just let him make those jumps, but actively let him fly.
I remember this was a Disney movie in part because there were scenes with the Disney characters (played by people in full-body costumes), got a crate with the bike in it, and I think there was a bit where Goofy, while riding it, started rising in the sky out of his control.
I feel like I've found this movie before... the title might have involved "Mike" or "Mikey"?