Comparison of crank based leg mechanism/extra simple walker
The "extra simple walker" based on http://www.instructables.com/id/Extra-simple-walking-mechanism/ is not relevant enough for its own wikipedia article.
However: Beeing very simple makes it a good base line. The mechanism is by no mean ideal, but it is possible to build a vehicle around it.
The basic mechanism looks like this:
The vehicle looks like this:
So. lets look at the walking vehicle:
The green base plate is going up and down a lot. It would be a very hard ride, just from the up and down. Not as easy to see is the speed variation:
Now take a very close look at the animation: