§ 73.02  RIDING ON BICYCLES.
   (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 1 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 back pack or sling.
(ILCS Chapter 625, Act 5, § 11-1503)  Penalty, see § 70.99