I have no idea what a rail is in a bicycle drive train. Check this link http://casanovasadventures.com/catalog/bike/p2016.htm or others available by searching for "bicycle parts diagram" and use standard terminology in the future - thanks.

To make sure the "rail" (and the rest of your bike) is ready for such a ride please get it adjusted properly once then take advantage of the resources listed under READ THIS at the head of this forum to learn for the future. Combining written/photo help with videos should get you well on your way.