Originally Posted by
Doge
Depends who you are and what you are doing. Your 19lbs vs 15lbs matters for racers But most competitors ride very similar equipment, so brand X vs brand Y are pretty close. It matters in the riders head too. The head matters a lot. It matters in TTs which are core to so many races and often won in fractions of a second over several thousand seconds.
Does that mean it matters? Just depends on what is important.
Weight is actually not that important in a TT. Aero is important in a TT. My TT bike is my heaviest bike but also the "cleanest". In that most of the cabling is hidden from the wind (we could do better though, next project is the brake cables). Even my brakes are hidden. The frame is narrower than the wheels.
Yes, it takes more effort to spool up a slightly heavier bike (I say slightly because my TT bike is not actually heavy, its just heavier than my road bikes) but it also holds energy better than a light bike- it naturally smooths out your TT power and personally I find the momentum that the bike carries to be hugely helpful in avoiding the necessity for power surges that would put me into the red power-wise.
Completely uttterly 100% agree with you though that equipment matters much more for some endeavors than others. For casual riding, decent stuff that doesn't break is often good enough. For racing, equipment hugely matters. Racing is about accumulating enough advantage over your competitors to have a shot at winning (or at least not embarrassing yourself). Some of that is training better, some is racing smarter, some is equipment choices. You'll see arguments here in the 41 that some bike upgrade is not worth it because it "only" gains you 1 min over X distance. The implication is that anyone who will pay $1000 for a minute is a fool. A minute in a 20k TT is huge though, you are blowing your competition out of the water if you win by a minute. So it makes sense to consider spending the $1000 in that context if you can afford it.
I also think that sometimes its just plain nicer on a qualitative level to ride nicer stuff. My endurance road bike is just smooth to ride, really a graceful thing that's great for climbing climbing climbing. My livelier road bike is just a quick little responsive thing that is so much fun on group rides. My TT bike just keeps going and going and there is something about it that makes me want to never stop pedaling, it think its the weight and the wheels. They all just *feel* way better to me than my old entry-level aluminum road bike, which certainly got the job done. But I don't like it as much to the point that I won't ride it any more. There's also nothing wrong with getting good stuff- bike or wheels or electronic shifting- because you like it better. The difference is by no means imaginary.