http://www.trueflightfeathers.com/facts.htm

Why do feathers give better guidance?

The surface of a feather has a slight roughness which helps "grip" the air flow. When the arrows yaws, this added grip helps realign it quickly and efficiently.

The huge weight saving with feathers also helps stability. Any weight added to the rear of the arrow (like plastic vanes), makes the arrow LESS stable. Add too much weight on the rear and the arrow will try to swap ends.

Finally, as the fletching crosses the arrow rest on release, feathers simply fold down out of the way, then pop back up. Plastic vanes bounce the rear of the arrow far out of alignment. This large deflection causes a substantial arrow "swing" which is only aggravated by plastic vanes weight and lack of "grip".

Does that "swing" matter?

Yes! While the arrow is yawed, aerodynamic forces are forcing it AWAY from its original path. The arrow is no longer going where it was aimed. Due to the sluggish straightening ability of plastic vanes, the arrow typically oscillates from one yawed condition to another. This yawing cost speed, range and accuracy. What's more, the penetration upon impact of a yawed arrow is lower than an arrow flying straight. The yawed arrow is trying trip itself, dissipating energy in an attempted angle penetration.

Hm, ich hätte sweep gedacht, aber vielleicht findest Du ja auf der Seite noch was. Die beschreiben es ja ziemlich ausführlich. Es gibt auch noch viele andere Seiten ;o)

Danke, das hilft mir schon weiter! Ich wusste einfach nicht, wo ich mit dem Suchen anfangen soll :)
könnte man diese Form, also den Schwung in der Feder, mit "inclined surface" umschreiben? (eine direkte Übersetzung hab ich immer noch nicht wirklich gefunden...)

edit: falls noch einmal jemand danach sucht: ich habe mittlerweile in einigen Artikeln den Begriff "natural warp" gefunden, der mir recht passend erschien.