Originally Posted by
jimmuller
What we don't know is how tire drag, low though it may be, varies with speed.
Power required to overcome tire drag is roughly proportional to speed. Power required to overcome air drag is proportional to speed ^3. But at 18 mph with good tires, the tire component is still typically >25% of the total. And some tires have twice as much drag as others.
The "open tubulars" from Vittoria, Challenge, and Veloflex are all fast and ride nice... and are fragile. Continental GP4000s are an excellent combination of speed, durability, and longevity.