(A) A person propelling a bicycle shall not ride other than upon or astride a permanent and regular seat attached thereto.
(B) No bicycle shall be used to carry more persons at one time than the number for which it is designed and equipped; except that, an adult rider may carry a child securely attached to his or her person in a backpack or sling.
(625 ILCS 5/11-1503) Penalty, see § 70.999