My roof rack won't tighten down enough to where it doesn't slip around. Anyone else having this problem?

I discovered it when I was putting a ladder up top and I grabbed the rack to pull myself up and the darn thing slid down the channel. I tried it the others and they did too. I took it apart and retightened everything but they don't seem to tighten any more. OS I am replacing with the thule rack system I think.

 

i notice on mine in only fit in certain areas so try moving it left ir right the handle should tighten it up

 

Same thing here. When I added the crossbars some areas seem to have it snug while others it is loose. Just try different areas of the rack....Good Luck!!