That has nothing to do with MotoGP games, it's about 3d models and their UV maps
UVs are planar projections of 3d models on a plane. You use them to texturize each polygon in the most straightforward way.
The problem occurs when the some parts of the UVs are stretched, for some reason (mainly because the UV map wasn't made in a clever way.
Look at this:
The top and the bottom polygons are stretched, and that will result in a stretched texutre in game.
The only thing you can do is to stretch your texture in the opposite way to compensate the distortion
Because you can't change the UV map of the model