Originally Posted by NomarsGirl

I guess my point is that it is nice that we have choices. Some will choose to put on the widest tires that the bike can handle. Some will stay with the skinny, high-pressure tires because they like them or want the bike to look as close to original as possible.

I understand the principles of physics. But the optimum tire size/pressure does assume a perfect road surface and a certain level of efficiency of the rider. The pros are much more efficient than us mere mortals. A rider who is feeling sore from every bump in the road isn't going to be as efficient as one who is more comfortable on the bike. But at the same time, really big tires are just going to feel heavy and sluggish and that will wear you down too. So while you can crunch equations all day, the truth is the best tire is the one that works best for the individual rider allowing him to have his best ride (which isn't necessarily the fastest ride).