For the angler who has never fished for chub before, I will give you some indicators as to where you will be most likely to locate them in your local rivers. I know of one or two still waters that have a few chub in, but they rarely ever hit lures. Location River chub like to hold in well oxygenated areas - like, for example, weir pools, back eddies, and just down river from weir pools. They like to hold and ambush their prey from structural features - like, for example, fallen trees, dense weed beds, undercut banks, or any other obstacle that offers shelter from the flow. I have learnt a lot about chub by just watching them working the flow.
Lure size can make a big difference to the strike rate.
When hungry, chub will happily take small to medium size plugs. I have found trotting flies down on the flow, after being cast well up the flow, takes some beating. A pair of polaroid sunglasses helps me greatly to spot chub hiding under weed. An accurately cast fly rarely ever fails to get the attention of at least one chub. It really is nice to watch as a chub glides effortlessly from its holding spot and tracks the fly as it moves down river with the flow.