View Single Post
Old 07-08-19, 10:05 AM
  #27  
HTupolev
Senior Member
 
Join Date: Apr 2015
Location: Seattle
Posts: 4,261
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 1971 Post(s)
Liked 1,297 Times in 629 Posts
Originally Posted by Sy Reene
Not sure I understand how Enve, as a performance-based marketer, derives their charts though. Eg. looking at an SES 3.4 chart.. 25mm tire, 150lb rider, inflation of 60psi. Ok, but how do you reconcile this with eg. data from BicycleRollingResistance, which will show better performance at higher PSIs than 60. Scroll about halfway down: Conti 5kTL
BicycleRollingResistance holds the tire rigidly against a drum, the data isn't accounting for the tire's behavior as suspension. Pumping a tire stiffer will always make it deform less against a rolling surface, but in the real world, you tend to get better performance if the tire is deforming around irregularities rather than transmitting deflections to the bike and rider. Comfort is speed; the energy spent making you uncomfortable when tires are pumped too stiff is energy being stolen from your forward momentum. The lighter the rider, and the rougher the surface, the squishier the tires need to be pumped to do their job properly.
HTupolev is online now