Cheers Brummie, is that the second bolt from the front??
The pinch bolt is the one that the cable goes in then you tighten up to secure it. I love tweeking my brakes, I could spend hours getting them right.
If one side is moving in & out when you pull the lever & the other is sticking to the rim then first of all the whole caliper may not be central to the wheel. Undo the pinch bolt or undo the adjuster so you have plenty of gap between the pads & rim, then undo the nut on the back so the caliper becomes lose, then shift the whole caliper over so the sticking shoe is well away from the rim, pull the cable back through & adjust & see how they move. Hopefully the stuck side should be moving in & out now. If so then pull the cable through & adjust & away you go
If not then undo the caliper again & take it off, the rear spring behind the arms prob needs a good stretch. Its also a good idea to dab a spot of grease where it slides on the caliper arms. Pull it out so its nearly straight then hook it back in again & repeat whats above.
that will sort it....unless you have the wheel wonky in the drop outs
