I did a pretty ggod seach on this same subject awhile back when I was going out there for a long weekend. Found nothin g immediatly around Luray except for ALOT of hills and of course Skyline Drive. I did find some rides not to far away on the Winchester Wheelmen website. You might want to check those out.

http://www.winchesterwheelmen.org/where.php

Good Luck.