What kind of preparation did you preform? You have to sand them heavily to remove all shininess before even thinking of paint, then use some grease remover to clean the plastics then paint, once you have have sprayed with krylon fusion you need to put around 2 coats of clear. You also have to let the krylon cure for 24 hours before riding. I havent tried this myself but have done a good amount of reading on how to paint plastics. I have heard with the proper prep fusion does a good job holding up.
