Came across this: http://cyclesetforme.blogspot.com/
So if I'm interpreting the results correctly - about 10% lower rolling resistance going from GP 4000S 23mm to Corsa Speed 23mm. Average size rider at 25mph and you're looking at about 3W lower rolling resistance I believe.
So if I'm interpreting the results correctly - about 10% lower rolling resistance going from GP 4000S 23mm to Corsa Speed 23mm. Average size rider at 25mph and you're looking at about 3W lower rolling resistance I believe.