I currently have 500-5 Cleveland wheels part #40-78B on my KF Model 4 and they're just not very big. I'd like to get a pair of 850-6 on it. (I think this is a good size for the KF 4?)

I have Grov gear, Cleveland brakes.

The question I have is how do I know if a wheel assembly will fit on my axel's?

Will a 850-6 Cleveland wheel fit right on?

My plan would be to trade or buy a new set of Cleveland 850-6 and sell my old ones.

Thoughts or ideas on this?