Don't under estimate the protection factor of Armorall Tire Foam for plastic and metal parts - You can spray the entire bicycle with multiple coatings to leave a thin coat of protectant on all the parts - This will also slow down dry rot on the nonmetal surfaces...
My discovery of this products use was accidental - I sprayed and old Huffys' tiers with the foam and promptly forgot the bike behind my nephews shed - 7 months latter I noted the tiers will still black and over spray of the foam had protected some of the metal parts...