I searched the forums and read through some of the old Saris bones posts, but I still had a couple questions. Do you really need the bike beam bar to make if you have a sloping top tube? What will it affect if the bike is angled while it is sitting on the rack? I don't think this will be a problem with my road bike but my mountain bike might be more of an issue. Also how safe are the locks that you can buy for these racks. I haven't received my rack yet, (it is coming in the mail), but it seems like someone could just cut the straps and throw the whole rig with the bikes in the back of a truck if they wanted to. Anyway any response is greatly appreciated. Thank you.