I'd swing a 10x7 for all around performance for a trainer. Lowering the pitch/diameter allows you to wind'em up as Fatsky stated, hardly what you'd want for training. Personally, I wouldn't bog them down with 11x7's.

Using a certain prop to slow a trainer down, is not necessary in my book. The ONLY time I would ever use a 12" prop on an ABC 2 stroker, is if I was flying a Cub....and that'll never happen.


Best thing to do is try a few different props, and use what you, your plane, and your motor like the best.

Gary