u/easter_egger

I ve read this https://www.reddit.com/r/discgolf/comments/u7m2xf/everything_you_could_want_to_know_about_flight/ and read that the height of a parting line defines the turn (hss) and fade (lss). Tldr according to this a heigher parting line equals less air resistance to the top which translates to less turn aka more overstable. For fade it just states gyroscopic percession and the heigher the parting line the more fade it will have as the height of the bottom part influenced this.

This raised the quesiton how a high negative turn value (understable) high fade value (overstable) disc or the other way around are even possible to exist.

After that i watched this

https://m.youtube.com/watch?v=fL4DhAMiiHI&t=426s

And now i am very much confused.

This video states if i understand it right, that the speed of a disc changes where the lift force is applied. And because of the gyroscopic percession then gets tilted to either side. If the speed is higher the lift force should apply behind the center of gravity and therefore turn the disc anhyzer. If the speed is slower in front of the center of gravity and therefore turn the disc hyzer.

Therefore it should apply according to this video on turn and fade. No word of air resistance and instead only gyroscopic percession as explanation in comparison to air resistance as the first articles states. Should not the resistance have nothing to do with the parting line as it the same amount of air is over and under a disc in total if you would have 2x of the same disc with a heigher and a lower parting line?

I dont really unerstand if a heigher parting line generates more lift or a lower parting line and why. And how it changes the fade and turn as he says the speed influences the point where the force applied not the strength of the force.

This video states if i understand it right that if more air is over the disc in comparison to under the disc the lift force is heigher, so that a lower parting line generates more lift than a heigher would as a heigher line means less air over the disc and more under it. This i really dont understand. Why is this? In my stupid mind i thought that more air under it means a higher lift force and therefore a heigher parting line equals more lift. But this video said it is the other way around. What is even true and why? Also the following question what does it even have to do with turn and fade. Obv a higher lift force means higher hyzer/anhyzer angles but is not this lift force also glide related? But as we stated the point of applience should define if its hyzer or anhyzer. So how does the parting line even influences this behavior?

Obviously i am very confused so if someone could explain to me the correct physics and the influence of the parting line on it to me in an easy to understand way id be very thankful. This topic drives me crazy atm.