Originally Posted by
adrien
Maybe, all things being otherwise equal, a pound or two.
I have two steel bikes and a ti. I ride carbon all the time, because I travel a lot and rent bikes. If you want a higher end bike (say from a shop that will set it up for you when you go rent it, based on an emailed fit chart) it will be carbon. My steel bike has a steel fork, and weighs about 20 lbs (it's a 60). Ti bike is about 16.5-17. High end carbon bikes, the lightest I have rented was a Pinarello, and it came in at about 16. Bear in mind that the weight you have to move down the road is the bike plus you. So let's say the two together in my case (I weigh 210) will run from 227 to 230 pounds. That's a total difference of about 1-1.5%
Weight is generally pretty close, and sometimes heavier, for carbon vs. steel vs. Ti. The same level steel (high end, with carbon fork) compared to the same level carbon, the carbon will be lighter. By something like a half-bottle of water in the cage. Yes, cheaper steel will be "heavy". So will cheaper carbon, by the way.
Then the question is does that matter? Well, things like wheels and tires will have a much larger impact on feel, and things like position (wind resistance) will have a bigger impact on speed than weight. And I can lose a pound overnight, personally. Now, long climbs at over 10% grade -- there, you will feel it.
Yes, a stiffer bike jumps faster when you get on it, and a lighter bike will also give you that sensation to a lesser degree. Stiff + light will really feel jumpy when you hammer it. But the focus on carbon is marketing-driven. Pros ride it, it is advertised a great deal, and comes in product cycles. It's the production profit engine, so you need the latest one to be fast. And you'll need the latest one next year, too.
BTW, there is a pro team in the UK riding steel.
There were weight weenies long before there were CF, Ti or Al bikes. It is an avocation. There is body weight, and there is bike weight. They need to be combined to know the effects of forces on the motion of the bike and rider on the road. But not for any other reason. Light bikes are their own reward just like losing body weight is its own reward. You should quite trying to rationalize the desire to lighten bikes. It is just something people like to do.
And BTW the difference may be a full water bottle, but that will always be the difference. You don't ride without water to lighten the bike. Just like once you lose body weight, there is still that bike weight to deal with. One doesn't affect the other.
As for a Brit pro team riding steel, that is just meaningless. Exceptions to rules happen all the time without affecting the significance of the rule.