I don't think that Flying saucers are a substitute for an upright wheel.They just don't compare,other than being called a wheel.They don't allow a natural running position,they cause side arching,and no matter what size you get you'll never have the same amount of running space as you would with an upright wheel of the same size(which also happens to take up less floor space,meaning you can have more valuable enrichment).For example,a 12 inch upright wheel would have 6 inches of running space which is appropriate for Syrians however a flying saucer of the same size gives 3-4 inches in most cases that isn't even ran on straight
