Originally Posted by
Otis
A bicycle is to convert human power to forward motion for transportation, recreation, sport, etc. A good bicycle will capitalize on design and materials to make it as efficient as possible for its intended use. Power to weight ratio is everything, and the weight of the bike counts.
Why do you think it does not matter?
One reason is that at most riding speeds without steep hills, the dominant source of resistance to motion is air resistance. Weight has nothing to do with applying this amount of pedal power.
Weight does affect the resistance due to rolling resistance, but the relative value of this factor is usually considerably less than the air resistance.
Caveats: Not if you're going uphill or downhill, and not if you don't ride "fast enough," and not if you accelerate a lot on some specific route.
Plus over brevet distances, even small loss factors can make a measureable difference.
So it isn't really right to say it DOES NOT MATTER, because there are condition where it might be dominant. The question is, how significant are these brief events considered over a lengthy ride. It is correct to say it is not significant for most riding, at least in my town.
If you think it is very significant, what are you doing messing around with old steel bikes?