Originally Posted by kvda
@JeanMarc: That test in the German Surf Magazine also showed that a carbon end in a aluminium boom doesn't make the boom stiffer, but it's much more expensive.
check the difference between the NP X3 and X6:
NP X3 € 230/ 27 / 22
NP X6 hybrid € 449/ 28 / 23
Sorry, I don't agree. It's not zero difference. There is a very small ("sehr geringen") difference, both subjectively when riding both booms and objectively at the lab test (both with +10 cm and +44 cm extension). The carbon tail does stiffen up the boom. It's not spectacular I agree in the case of the X3 vs X6, but it's significant enough to be felt and distinguishable. Whether the price difference justifies or not the small gain in stiffness is another question of course...