Problem with G-Force

[Ant29]

Can anyone help with this roller coaster? When I start the initial test and allow it to run it's first cycle it shows the first rating for the g-force but when I let it continue, it says it exceeds the g-force.
Does anyone know the limits or where I might be going wrong here?
There is 4 trains on it.

 

[Suzie2909]

Hello !
I'am not playing Planet coaster for a long time , but I understood Vertical G force may also be too big if the train is Going slowly or faster sudenlly .... or too vertically or downly also big time.
And sorry for the maybe strange english as I'm french !