I switched to the Atlas Flex track for my ceiling mounted train bridges since the demise of K-Line my ex supplier. But since the Atlas O flex isn't being screwed down to a wood base like on a normal layout i couldn't bend it properly, so i came up with a roller to roll the track perfectly. Its a little time consuming tearing the track apart then putting it back together but it holds its shape well...Bob http://new.photos.yahoo.com/aametalmaster/album/576460762401121042