I hate to criticize when I know you're half-joking, but, to me there's two errors here that we often accuse people of misunderstanding about evolution. So, I think it's important to avoid the errors, even when we're joking around.
First, your bike is being modified in ways that is not incremental at all--you have "full features" (i.e. a battery-powered light, generator, etc). This is EXACTLY analagous to the mistake that creationists sometimes make, expecting a feature such as an EYE or LIMB to appear suddenly, not incrementally. This leads them to the conclusion that "the probability of all mutations necessary to make the change would be too low for them to actually occur simultaneously" which we then HAMMER them for. It has to be incremental.
Second, your "selection" is not based on natural pressures, but instead what you view to be "good." Of course, this mistake happens all the time--people think that evolution must mean "improvement." But all it means is change due to "selective pressure." You have selection, but no selective pressure.
I actually think this exercise is interesting too. But I was thinking of something more along these lines:
- adding features which are incremental extensions / modifications of existing features, incorporating things "endogenous" in the environment around the bike.
- using "selective pressures" as I see fit (in other words, I can choose whatever 'environment' I want, because it's just a stupid exercise)
1. The 'environment' where motorcycles evolved from bikes involves an interesting history. At first, in this environment, bikes were only used to travel downhill. Once downhill, people used other machines to drag their bikes (and the water & food that they gathered in the river in the valley) back up the mountain.
1. Bikes with bulky masses around the petal area (extension of an existing feature) become selected for, as lighter bikes proved to be less stable and more susceptabe to friction. People tended to select bikes which didn't crash as easily and went faster.
2. (The bulky mass evolves moving parts to provide a more comfortable ride [this can be done incrementally; still working on a bit of this]) People tended to select bikes which had comfortable rides.
And on like this. Gas can be added due to environmental considerations (maybe the people struck oil at the top fo their mountain, and started bringing it downhill to ship it, or maybe the people living at the river because super-in love with mountaineer's fresh tempura (fried food), and so that turned into people cooking tempura while riding bikes, etc), just like anything else. By the way, I think it would be fun to develop a more incremental version of bike->motorcycle together (talking about everybody) here.
Anyway. Didn't want to "rain on your parade" or anything, and I know it's just a joke, but I really think it's important to follow our own points, even within jokes. And since I've found you to be a really strong, knowledgeable poster here, I'm pretty sure you can appreciate that.