UPDATE:
Finally logged back on to Steam after a long absence and was delighted to find out that it has a custom controller mapping interface. Just click on Steam upper lefthand corner, then Settings tab, and finally Controller tab. If your Thrustmaster Freestyler Bike Controller is plugged-in, it will say so at the top of the page with a button for Setup and mapping of buttons/triggers!
Finally logged back on to Steam after a long absence and was delighted to find out that it has a custom controller mapping interface. Just click on Steam upper lefthand corner, then Settings tab, and finally Controller tab. If your Thrustmaster Freestyler Bike Controller is plugged-in, it will say so at the top of the page with a button for Setup and mapping of buttons/triggers!