I didn’t say “FTP.” I said “power,” because that’s what Jan Heine said. I’m quoting Heine directly because I’m trying to take his idea seriously and to respond to the specific parts that I think are wrong. Other people in the thread have said FTP, but I’m not one of them. You’re saying that this claim of a 12% power increase is an anecdote about a single rider, and that’s great! I agree completely! But Jan Heine says that this anecdote proves planing, a phenomenon he defines as allowing riders to produce more power, is real. Meanwhile, another of the interlocutors in this thread has been lambasting me for rejecting this isolated data point. I get that you all aren’t coordinating, but no one here seems to agree on terms or even to be defending Jan’s actual definition of planing, instead selecting a definition that makes sense to the person writing the post. So I’ll lay out the three major categories of planing people seem to be arguing for.

1. Planing is real, strong form. This is Jan Heine’s idea that a bike that planes allows the rider to produce significantly more power, over essentially all durations. This is the idea I think is basically unsupportable given everything we know about physiology and material properties.

2. Planing is real, weak form. This is the idea that frame flex is beneficial and a flexible bike can be faster than a stiffer bike due to factors like a stiff bike causing the tires to skip about. I think this idea is very plausible but the range of circumstances where a bike could have too much drivetrain stiffness is probably pretty narrow. British Cycling has been brought up in this context, and since British Cycling is mostly concerned with track bikes, which have very short chainstays and very skinny tires, that makes sense to me. I don’t really believe that any bikes being used in professional road racing are losing power due to excessive stiffness. With 28 and 30 mm tires now standardized in pro racing, I don’t think a bike in the style of the French constructeurs can plausibly be faster than a carbon fiber superbike on this basis.

3. Not even planing. This is just about the ineffable and romantic qualities of a bike with a really magical ride quality. It’s the feeling of floating over the road while still feeling connected to it, of the mix of comfort and liveliness that the best steel and titanium frames are renowned for. This is definitely a thing and bikes like this feel great irrespective of how fast they are. They’re a joy to ride. It’s just not at all what Jan Heine means by “planing.”

It seems like you’re arguing point number 2, and as I said I don’t really have much of a beef with it. I just a) think the real world circumstances where a bike could be too stiff in the driveline are very rare and b) don’t really think this is the key idea of “planing” as described by Jan Heine.