Yakima Rack Problems

The round bars on my Yakima setup slip and roll no matter how much I tighten them.  I got these in the dark ages when round was the only choice, unless you went with Thule and got square.  The saddles in front and especially the Hully Rollers in back somethimes slip independently of the bars.  Is there something I could put on it to increase the friction without making it impossible to remove?  Actually, I keep the bars on my pickup shell all the time, and could probably use locktite there if that would work, but I need something that would allow me to detatch the rest if I need to haul some lumber or something.

I don't have round bars on my roof rack but I still cut up a bike tube to layer in between the kayak rack mount and bars for extra form and grip. It works well

(get a mountain bike tube, not the skinnier road tube)

yes!  the major drawback of the round bars.  That and whistling is why i ended up going thule or inno.

I like the tube idea.  the other is shelf liner or grip tape

Well, after I got into it, I realized that, while the towers that go on the SUV have a single adjusting screw tightening the bar to the towar and the tower to the side rails, the tower for the camper shell on my pickup has a separate nut that tightens the bar and another screw to clamp it to the vehicle.  The tower actually fits the bars too closely to use an inner tube gasket or thick 2 sided tape, but thanks for the suggestions.  I tightened the top nut as much as I could after using a little thread lock compound.  Haven't loaded up the yaks yet.