Re: Faster is safer. What are my options for a bit more speed?
I'm questioning your idea that "Faster is Safer". As a statement of fact without anything to back it up it is utter nonsense. Without better tires/wheels, brakes, stronger frame the opposite is true. Faster is more dangerous. These are bicycles being asked to become light motorcycles which they were not designed for. If we want to make them into light motorcycles then we need to be concerned with upgrading/ transforming the whole machine and not just focusing on how to make them go faster. It is simple, really. Put the biggest motor on it you can make work, say a prayer and take off. And good luck.
At the risk of sounding like a crusty old fart (which I am), focus on the whole bike and keeping yourself safe. If you want to go fast, then do it and have fun. But broken bones and hospitals are not fun. There is a great temptation to buy a cheap fat tired cruiser from a department store... see that you can buy a 212cc four stroke on sale for a hundred bucks and imagine that you can make it into an inexpensive light motorcycle. In my opinion that is an illusion.
By all means build a motorized bike. But keep it reasonable, upgrade the whole bike and stay safe.
Someday when I grow up I will probably lose interest in toys with wheels, but until then...