Foam tine protectors are inserted in between the tines when they are shipped from the factory. It is recommended to keep these and re-insert in Choirchime® tubes B3 and lower at the end of each use. If you travel with your bass chimes, it is imperative to have these foam protectors in place due to rough handling by most shipping providers.
If you have trouble fitting the protector in between the tines, do not force them. You most likely have bent tines and by forcing the foam you are adding to the stress on the metal and premature failure is likely.