the wooden prop's purpose is to break before i pull out another firewall. btw anyone building the US 40 plus reinforce the firewall. where the top piece that connects to the turtle deck. its a weak point where the firewall can split down due to the fact that the blind nuts go thru the joint weakening it. thats why i want a prop that will break on the off chance that i get the plane to nose forward and dig a prop into the grass. on concrete its not a problem i would have to change a prop anyhow even if i rake a composite prop because then its off balance. bigger wheels would add un-needed weight.