With a larger wheel, you have more contact with the ground, so you have better traction whether you're braking or cornering or any of that stuff. Also, with bigger wheels, once you get them up to speed, they roll faster.
In sooth I know not why I am so sad. It wearies me, you say it wearies you; But how I caught it, found it, or came by it, What stuff 'tis made of, whereof it is born, I am to learn.
The Same, the Same: friend and foe are of one stuff; the ploughman, the plough, and the furrow, are of one stuff; and the stuff is such, and so much, that the variations of form are unimportant.