Be interested to know if people are hair rigging or not; given most of the baits i suspect people are using, i would suspect they are? If so, then if, we are talking a short hair (a must for Barbel imho), i would contend at this point, that striking isn't needed 99% of the time. My approach and thinking below is based on hair rigging. The longer the hair, then the more reliant you are on the angle the fish mouths the bait from being right to then set the hook with a strike. Too long a hair and dependent on the size of the fish and subsequently its mouth, i just feel costs you Barbel sometimes.
@Scribe if you are using the ones i tied you up, then hair rig and short hair is what i know you use.
Barbel mouth the bait, feel the hook or that something isn't right and usually bolt, which sets the hook-hence no need to strike. With side hooking with larger baits i would say that striking is more important, due to the nature of the bait taking most of the hook, bar the point (important not to bury the hook completely for fish safety), say a large peace of meat perhaps. When using maggots however and side hooking them, i have never needed to strike nor observed many knocks and bangs in between. Although i only go down the maggot route in extremes of temperatures-high and low and not necessarily therefore when there are many Barbel around or at least not large shoals feeding, which can cause knocks and bangs.
When i say usually bolt, it has been known when fishing with smaller baits on the hook and in sizes similar to the feed, Barbel will look to continue to look to feed. When a larger bait is taken they drift away to eat it in peace and to wait their turn again at the back of the shoal. However, again, i think if you are fishing a short hair, then you are maximising the chances of a hook up. Sometimes and remembering that Barbel's stomachs are relatively small compared to other cyprinids, its not uncommon on taking and eating a larger bait, for the fish to have had its fill, same if eating several smaller baits, which is where you want the herd of cattle mentality to kick in for a bumper session to occur, some keep feeding, so the others do, actually hungry or not, but not wishing to miss out.
The odd bang or knock here and there could be anything coming down and catching the line, or equally a lone fish or one part of a small group could brush the line, spook and take the rest with them, hence the single knock then nothing. I'm not suggesting there is no need to watch the tips, it can be good for reading what might be going on at times when there is a bit of activity. But just like the hair rigging aspect, i would suggest watching them with a view to striking at them isn't necessary, its a case of rig mechanics for me.
This one also links to when some say that the knock was a fish brushing over the hooklength, impossible that a fish doing this would register anything on the tip, if we are talking a lead or feeder set up. The mainline is anchored both ends and taught and anything touching that would give an indication of course, but the hooklength, no, until of course pulled tight by a proper hook up. If a bow in the line method, then this would after a brief pause and depending on how far the fish bolts, will then register. I wouldn't fish a bow near snags ever for that reasoning of giving the fish some time to get in them.
For me, constant, knocks, bangs, taps and rattles are fish, and hopefully Barbel in a shoal and in a fully focussed feeding mood, to a point where catching the mainline does nothing to dampen their enthusiasm, hence they continue until you catch one. Sometimes and actually when on a feeder approach, i would rather not have these indications and run the risk of them spooking, as it can be a sign to me, that i have cast the feeder to far down stream and right in the middle of the feed that has worked its way down, from my more accurate upstream casts, using anything from a 3ft to a 6ft hooklength, i want the fish that sort of distance from where the feed is initially settling.
Leaving the fish somewhere to feed in comfort is important, as is sometimes taking the rig out completely when you get these sorts of indications, to eliminate the spooking risk and thus encouraging the fish go from interested mood to carefree feeding mood, which is the point at which you catch them.
I have heard before of people suggesting striking at some of these little indications and that you would be surprised when you do, so not the first time and i could have it completely wrong, but its not for me, due to the rig mechanics and also the potential for disrupting the swim more than is necessary in doing so.
