Klein and Sommerfeld (1910): It appears to me that the last part of this work, which contains the bicycle model, was published in 1910 after all. Previous parts were published from 1897: part 1, 1897; part 2, 1898; part 3, 1903; part 4, 1910. The last part has the line 'bearbeitet und ergaenzt von Fritz Noether' (edited and completed by Fritz Noether). So it is possible that Noether actually derived the equations. JPM, Nottingham, 8 Nov. 2005.