Where and how have you been fishing for them? To add to wiseys point, if we are talking hair rigging, then bait needs to be close to hook-short hair or hooked directly. Chub peck at baits. Some when fishing for Barbel for example will intentionally use a long hair to avoid chub because of this.
If its float fishing, then maggots and plenty of them. Stick float if fishing the line along the rod tip, or waggler if running a line further out.
To get to the fish or keep them coming during a session, changing depths is sometimes needed. Waggler wise I did a bit of a write up on a decent session I had on the Nene this summer- in where you fished today section.
More intimate rivers or backwaters, free lining can produce if you are targeting bigger chub or ones that you can see. As the name suggests, literally just a hook, may be a single weight, with breadpaste, breadflake or cheesepaste. Really shallow water, you can float breadflake for them-really fun fishing.
If deep water in larger rivers, the maggot feeder and a hooklength between 18 inch and 4ft works.
If it is a river where you have float or feeder options, check the water clarity before deciding on tactics. 18inches visibility or more is generally float conditions for chub.
