The kicker.challenge.gbx file you have requested: Tracks / Kicker - 3.48kb is not available. Perhaps try browsing all files for the game TrackMania Nations Forever and upload any files you want to share or are missing. This is the only information we could locate:
Nothing amazing really, but sufficient to have people finding just the right way to get around it. A decent time relies on getting the jump after the loop perfect. There are a few ways to go at different points on the track. Pick the right one! Don't be deceived by direction arrows.