Tadej Pogacar breaks 3 Strava records during his reconnaissance for Paris-Roubaix 2025 including fastest time on Mons-en-Pévèle

Not sure exactly what you are saying, but if you're implying that being heavier is helpful if you're going against the wind or sprinting, then no, it isn't. Ceteris paribus (all else held equal) being a lighter cyclist is always better, save downhill. The reason why heavier cyclists do relatively better than lighter ones on flatter courses is because they will have to have a higher power than the lighter cyclist in order to have any chance at all against them, and flatter courses mean that the lighter cyclist has nowhere to display the better power to weight ratio, meaning that significant ratio is power to CdA, which is usually an advantage to the heavier cyclist.

I am saying I have an open mind at the moment for your cobbles theory but cannot agree with your wind statement (and by extrapolation sprinting since that implies speeds where wind is by far the limiting factor). Had you argued all things not being equal I could have agreed with you but if we thus assume 2 objets of the same size and speed but with differing weights, it is completely obvious that the lighter one will suffer faster in the wind. Extrapolate to the extreme, drop stuff off cliffs or just remember your momentum equations to verify. Now, obviously in real life we have to assume riders of different weights won’t have the same wind hitting surface but you cannot generalise at all then as you can have very unaerodynamic light riders and very aerodynamic heavy ones because it isn’t weight that defines CdA, Teslas have an incredible CdA and are ridiculously heavy, and someone like Harry Levreyssen is a Tesla in cycling.

No, weight doesn't affect the ability to go into the wind at all. It's all CdA vs power at that point. For example, it's "obvious" that a heavier object falls faster than a lighter one. But, absent wind resistance, it's not true (Galileo demonstrated this). An appeal to "obviousness" doesn't matter when the physics is clear. And yes, you have to be able to hold everything else constant, or you can't determine anything! So, imagine a 300 watt rider at 80 kgs with a CdA of 2.0, then imagine that same rider at 70 kgs with a CdA of 2.0. (Assume ideal tire pressure for both, same bike.) Which one can ride over a bumpy road fastest? The lighter one, as he doesn't have to lift as much. That's also why when they test bikes on 5 star cobbled sectors, the MTB goes faster than even a cobble-build road bike. Even though rolling resistance is higher on a flat road, and the CdA is junk, it smooths out the cobbles, allowing the person to not lift as much as they otherwise would.

So why did Tadej say, in an interview, when he won Flanders and was asked if he would try Roubaix next, that he would need to gain more body weight before he thinks of Roubaix? Tadej weighs 25 lbs. lighter than MVDP, last I checked.

...Cause cycling at this level is always about the compromise of weight vs power. Pogacar could be stronger at a higher power, but his power to weight ratio would suffer. All else held equal is very important to understand they physics here, but that's *never* how cycling actually works.