cyccommute 

Personally, I don't care if you use your feet for braking or if you use neolithic tools for taking your bike apart but your ideas on science are way off base. I happen to do science every day. My job is to solve problems in ways no one else has done before. However, I have to know how other people have approached a problem in the past or else I'm just repeating the same mistakes that they have made and I'm going no where in terms of science. You don't start at first principles on every problem or nothing would ever get solved. In science...at least the science I practice...you build on the work of others and you acknowledge the fact that others have gone before you. In other words, if someone says you should probably do it this way, you might want to listen to them. You can do it your own way but you are going to go down a whole bunch of blind alleys before you discover that the way the 'experts' said to do it is probably a pretty good idea.

You might try taking your own advice. Go try riding a bike in traffic (remember the original question?) with only a rear brake. If you survive long enough, you'll find your hypothesis doesn't hold. And try a chain tool on a chain. You can do it the hard way or do it the way some other clever monkey figured out how to do it.