Always wanted to ask this question.
In props up to 13" in dia 4" pitches are easy to find. However when you go to 16" and 17" dias lower pitches are rare.

Secondly, on the sim I was trying out a 160FX on the Reactor 50cc. I found that a 16x4 or 5 just wouldnt give sufficient thrust whereas a 16x8 did seem to do well.

Even in the manuals for larger engines, recommended props seem to have higher pitches. So my 55ax has recomended 12x8 where as the 160fx says 16x12 or 17x10.

What gives?

Ameyam