Smaller Diameter Wheels - What's the advantage?

[LLogan]

I do not think that "more torque" is a justifiable advantage of smaller diameter wheels. It's possible to manipulate gear/sprocket ratios to cause a smaller wheel and a larger wheel to have the exact same torque and speed.

I don't think a larger contact patch is correct either, because wheels are circles and technically circles are tangent at only one infinitesimally point.... Of course, it's the real world, so the contact point is more than just an infinitesimally small point, but in order to have a larger contact patch, the wheel would have to compress a bit. Rigid metal/plastic wheels do not compress very well.

Thanks for input elsewhere, guys!