Welcome Kymco Owners!
Not 100% sure what you mean there but if the rollers have one end that has more plastic on it covering the brass inside then that goes to the left hand side when looking in to the back of the variator( ie variator sitting face down on the floor).Some rollers dont have a thicker end so these can go in anyway round. If you look at the sides of the ramps you can normally see soke wear on one side where the rollers rub more due to the centrifugal force as they move up and down the ramp.Hope that helps a bit.