So I have this motorized bike I made and I'm thinking about adding gears on to it over the summer. Anyways, it got me thinking and I'm confusing myself. So say you have an engine with a two speed transmission on it. For take off, you're in the smallest (or, biggest in size actually) gear so you can get some torque to get moving. Then, once you're up to a nice moving speed and the engine is purring at its prime RPM, you kick it up a notch to the second gear. Slowly, you get faster and faster until you hit that prime RPM again. Now, my question is, what determines the max number of gears you can go? Is it infinite? Like if you were on a flat plane, could you keep going faster and faster as long as you had gears to support it? If so, would that only work on a flat plane? What if you introduced a hill? Would it still work, but take longer to advance through the gears as you wait for the momentum to pick up? Thank you!