Please excuse my ignorance on this, but I'm a first time mini bike builder, and I don't understand how you determine which size wheel to get. What are the factors you determine in choosing a wheel size? I guess I understand the tire needs to match the wheel size..same as a car. Then does the wheel size you choose determine the size sprocket? How do you choose which side you out the sprocket on? Any information on these questions will be helpful! Thank you!