Oh No! A Propeller Question!
I will try my best to add something!. First thing to remember is that most motor testing is done statically and the thrust you can expect at top speed is just going to be a guess unless your model is going to be a slow flying entity. Add to that the fact that propellers are not all equal. I have had issues getting the stated thrust at times until I found the type of propeller that performed best.
As I do a lot of playing with high Kv motors of late I have found some counter-intuitive facts. For higher speed often a smaller diameter prop with a higher pitch is best. Often this diameter reduction can be used to fit a 3 or 4 bladed propeller of high pitch.
The range of pitch across the propeller blade span can lead to serious inefficiencies. The part of the propeller that provides good thrust at take off can actually be useless at high speed, and the part of the blade that provides most thrust at high speed can be stalled at take off.
Just a story from recent experience! A bix 2 had a mid air wing fold followed by the long drop and sudden stop. Anyway the owner was just going to bin it as he was bored with it anyway so I grabbed it and pieced it back together. The owner had removed the propeller and adapter for use elsewhere so I searched for a replacement. Originally it had a very noisy 6x4 2 blade prop but I had none so I grabbed a 5x4x3 that I had sitting around and took it out for its post repair maiden. I opened the throttle fully and the Bix took off like a scalded cat. It climbed out at around 70 degrees and was so fast that it was passing almost every warbird in the air at the time. Now the owner has it back, (a sudden change of heart?), and now hoons around buzzing the so-called high speed planes. The only difference from standard was the fitted prop.
If you want to go faster reduce the prop diameter and increase the pitch you may be pleasantly surprised at the results!
Just what works for me!
Have fun!