Rubicon Example

The gyroscope cannot reach exactly 0, so we need to help it out a little bit.
We plug the gyroscope into a Wrap Distance with a jumper set to 0 to detect when the gyroscope is pointing down. The jumper can be changed to 0.5 if you want to detect when it's pointing straight up.
The Wrap Distance is then plugged into a sqrt, then into a sub with 0.08 set (this can be increased to increase the angle threshold).

I hope this helps