I have roller mixes, some are 1/2 roller and 1/2 fantail but the others are 3/4 roller and 1/4 fantail (got them from 2 diferent breeders.) whats the chance of them rolling?
If you want rollers, you need to stick with rollers. Fantails are beautiful, but rollers perform. Try to find someone who will let you watch them roll, the buy a couple pairs. They are AMAZING! Keep your rollers and your fantails separate.
The bird that is mostly roller MIGHT roll a bit but you'll have to fly them to find out. I'm pretty sure the trait is recessive and it takes selective breeding to keep them rolling the way you want.
Check out this video. (I hope this threads goes through.) You can't get these from mixes. And fancy colors are not the factor. Find a breeder who raises performing Birmingham Rollers. And remember to have fun!
Generally in roller crosses the most you might get is single flips or tumbles nothing like you have seen in the video posted by mrsjim. I have some roller/homer crosses that will give me four or five flips in a roll, but nothing with any speed or depth. I made this cross to create something with more flying strength so that I could continue flying when the hawks are here. My pure rollers only get to fly from late April through mid Sept. because of Coopers hawk predation.