Join Date: Oct 2002
Location: Medway, MA
Bikes: 2011 Lynskey Sportive, 1988 Cannondale SM400
Generally, locks on a roof mounted rack will only keep honest people honest. This is further exacerbated by mounting a tray to a factory crossbar, which means that there is some type of common hardware connecting the two. Even my Thule system, which is mounted to the factory rails, could be defeated by someone who is intent on getting at my bikes. As for choice of systems, for an easy to use and well-constructed addition to a factory rack, I would probably go with Rocky Mounts over any of the big name systems.
STAR 3 Spinning Instructor
2011 Lynskey Sportive (Shimano Ultegra 10s)
1988 Cannondale SM400 (Suntour XC-M 7s)