rubbing noise while braking

So i have noticed that I have some rubbing, or grinding on the drivers side sometimes when I am going down hills and the brakes are hot. Happens maybe once a week or maybe even less, only when going down steep hills or long stretches of downhill driving. I thought it was just the dust guard or something minor but everything looks ok, its not bent. Its not a heavy grinding noise just slight rubbing in rhythm with the tire spinning, as i slow down the noise slows, as i speed up the noise does too. The pads look ok, and its only on one side. do you think it is a sticky caliper? anything i can try? thanks in advance.

 

no ideas?

 

did you look at the inner pads?

 

Stock wheels? My Ultra 146's grinded on the calipers because the offset was wrong.

 

yes stock wheels

 

i will take everything apart again this weekend. thanks guys