Diavolo performing his bicycle daredevil act (1905)
Here’s a crowd watching Allo “Dare Devil” Diavolo riding a bicycle upside down doing a loop and topsy-turvy somersault:
Diavolo coming to “Loop the loop” (1902)
A B: Short arc, to ease the downward momentum for the climb.
B C: Long, gradual rise, so designed to miminize the outward pressure greatest in this arc.
C D: Half circle, made small so that the wheel may get past the apex with the least possible expenditure of force.
D E: Wide downward art giving the least possible momentum on leaving the loop.
E F: Gentle slope to the ground.