I am often asked how to select the right size bicycle frame.  Unfortunately many bicycle stores are more interested in selling what they have in inventory than they are in getting the customer the correct size frame.  Sadly many of those selling bicycles are not serious riders or students of the sport of cycling.  I have heard sales people tell customers that a particular bicycle might be too much bicycle for them.  They must think it has a mind of its own and can bolt out of control.  If you are new to serious cycling I suggest you look for a used frame.  Remember, the wheels and components are, in my opinion, more important than the frame.  Also, do not buy a road bicycle with head tube and seat tube angles more than 73 degrees.

Pacelines you see in pro racing are organized. They have specific rules. But in big groups like you find in centuries or charity rides, things will be disorganized. This can intimidate even experienced riders.

Sooner or later you’ll find yourself in a big group amid some riders with sketchy skills. It pays to learn how to survive (and also make yourself welcome) in a crowd.

This question is often discussed even among bicycle racers and top professionals, and the correct answer of an "expert cyclist" is often based on half truths, false assumptions and failure to understand basic facts.  In reality the answer to this question is not straightforward and generally valid, because it depends on how the bicycle and tire will be used.  Therefore, only general facts with characteristics of available tire types will be listed here: