Originally Posted by
asgelle
That's unlikely. The change didn't come about by some collective whim on the part of riders. We have data from lab and field tests showing the advantages of wider tires with lower pressure.
Narrower tires require less material, so they are lighter. Same with narrower rims. Narrower also decreases frontal area, reducing wind resistance so when narrower time/'rim aero combinations are made, they will be faster than wide ones.