I'm going to get geared up before the season starts and give trotting a go again. I will be fishing some smaller rivers and i've got a couple of nice, old Drennan rods in 11/12ft for this. For the medium to large(ish) rivers i'm looking at 13ft to 15ft (perhaps 15ft ???).
What would the suggestions be? I want light and sensitive. The biggest fish i'd be likely to catch would be Chub up to 4lb (if i'm lucky!).
I can go to two or three hundred quid if needed (the wifes just had a new car so I won't need to sneak it in the house

).
On the centrepin front I have a small Rapidex thats OK on the smaller rivers. What would suggestions be to match the longer rod?
The bit i'm not really sure about is the diameter on the larger pins?? Should I be using a 4" or 4.5" ?
Thanks.