Originally Posted by
Six jours
Volume 5, Number 1, page 26, Bicycle Quarterly: "Tubular tires are faster at lower pressures." The statement is accompanied by a graph demonstrating the test results.
The fastest tire on rollers would probably be a narrow steel strip. But on real roads, a narrow steel strip would be fairly slow. So the suspension of air-filled tires decreases rolling resistance over less-than-perfect surfaces. The question, then, is "How much air volume is ideal for a given surface?" There is no single answer.
Hmm...
Hmm. . . . for some reason you snipped the last sentence of the last paragraph you quoted, "For smooth surfaces, Zabriskie has used 160 lbs. in his tubulars on a smooth TT course." Perhaps because Zabriskie's experience was at variance with Jan the tire salesman's "test?" Get on your own rollers and try it yourself, if you don't believe me. Do a run at 70 lbs. and a run at 140 lbs. to make it simple. The difference is quite astonishing.