Competitors must swing across 3 hanging wheels, with a one inch ledge on either side. The second wheel was placed higher than the other two wheels, so competitors would have to make sure their momentum got them high enough to grab onto the small ledge on the second wheel. After the second wheel, competitors would have to maneuver their way onto the third wheel, which was on a pendulum and therefore would swing back and forth, but the wheel itself did not spin. And finally, competitors must make a dismount to the landing platform to advance.
This obstacle was proven to be difficult, as numerous competitors who attempted it, failed to swing their away across, typically due to weak momentum. There was also a slight disadvantage with its placement after the Rolling Log, in which some competitors may have fell due to dizziness and/or lack of focus. A total of 25 competitors fell on this obstacle during Indianapolis qualifiers.
During Indianapolis finals, the third wheel was removed, creating a far longer dismount. Three competitors consequently failed on this obstacle.
The Fly Wheels returned on American Ninja Warrior 9, as the third obstacle in Los Angeles, with a similar specification from the previous season, with the third wheel was removed during Los Angeles finals (just like during Indianapolis finals). During Los Angeles qualifiers, 20 competitors failed on this obstacle, including Chris Workman. However, no competitor failed on this obstacle during Los Angeles finals.
During Celebrity Ninja Warrior: Red Nose Day, the obstacle featured 3 wheels, with shorter gaps between the wheels and all three wheels were placed on the same height, in order to make the obstacle easier for celebrity competitors. Among the 4 out of 9 celebrity competitors who attempted the obstacle, 3 of them (Nick Swisher, Ashton Eaton, and Stephen Amell) completed the obstacle on their first try, while Derek Hough failed on his first try, but trying again and succeed at his second try.
On Australian Ninja Warrior, the Fly Wheels appeared as the fifth obstacle in Semifinal 3, and was called as the Big Wheel.
- Compared to most qualifying cities, the Fly Wheels is an upper-body obstacle despite being as the third obstacle. The upper-body and lower-body (balance) obstacle between the third and fourth obstacle were switched in Indianapolis qualifying course on American Ninja Warrior 8, as the Disk Runner is a lower-body (balance) obstacle. This deviation will eventually continue on American Ninja Warrior 9 in:
- This obstacle is also one of the few obstacles, where bending the arms at a 90-degree angle is not recommended. In this case, putting the arms straight on this obstacle will give competitors more momentum to swing to the next wheel.
- On several Ninja Warrior's international formats (e.g. Ninja Warrior UK 3 and Australian Ninja Warrior), the third wheel (the pendulum wheel) of this obstacle was combined with the cargo net, with a trampoline at the starting platform. Therefore, competitors must jump from the trampoline and grabbed the pendulum wheel. Then, competitors must build enough swing and momentum to make the transition to the cargo net, and finally reached the landing platform to advance.