I have to (respectfully) disagree with your last sentence (above). Even when at speed, you and your bike are constantly influenced by a number of continuously changing conditions. Current slope or descent angle, the rate at which that slope is changing, wind speed and direction, road surface, etc. ALL of these will act as either an introduced braking force or an introduced accelerating force.

My experience:

A lightweight carbon bike makes it much easier to initially OVERCOME both types of forces. For example, if you encounter the braking force of a brief incline, 2 or 3 quick pedal bursts and you're back up to speed quickly. If faced with a suddenly-encountered obstacle on a downhill, the carbon bike and rider will stop more quickly, simply because there is less mass to slow. This is why lightweight carbon bikes control the domain of racing. Completely.

That does NOT necessarily mean a more pleasurable ride. A heavier steel bike will tend to stay in motion longer before responding to an introduced braking or accelerating force. A short incline? Yawn -your weight-based momentum will carry you through without ever NEEDING to mash the pedals. Steepening decline? Ah, yes, apparently I must apply those brakes at some point. :-) The need to respond is delayed; the simple pleasure of riding is thus prolonged.

Think "table tennis ball" vs. "bowling ball."

In the right package and on the right roads and in the right hands, the properly-maintained steel bike is simply a calmer, more pleasurable sightseeing platform, still capable of incredible speed and handling maneuvers, but not NEARLY as susceptible to unwanted environmental influences.

Hmm. I think I've just explained to myself why I ride steel 6 days each week . . . and carbon only 1.

Duane Behrens