As for removing/replacing the track, there was some good threads earlier (on the old forum?) about this. There seemed to be several comon themes.<br>1. "Sheet Metal Screws" (ie tapered threads) are not good.<br>2. "Machine screws" are better, but with thin cross-section of aluminum cross-beam, not enoughof the thread "bites" into aluminum beam, also not good.<br>3. Long bolts through beam, so that nuts are accessible on backside of beam, are not necessary. And, it means ther's a hole in both sides of the beam anyway.<br>4. Short machine screws with locknuts inside rear tube are preferred solution, but how to access these nuts inside a long tube elicited several interesting ideas, none of which seemed feasible when the originator mentioned he had a 16 foot beam.<br>5. Holes in backside of beam are quite common (e.g. NACRAs), These allow access to nuts by a nut-driver or small socket extension bar. These holes do not adversely reduce strength of cross-beam, if they are small, round and smooth-edged.<br><br>