My Dad knows how to avoid this, because he rides XC, he says to start with a new set of sprockets and THREE new chains, once the chain gets worn slightly, put on a new one, then run that one the same, and the next. Then put the origenal one back on. You should be able to run all three chains three times, in the end you are left with a complete set of knackered stuff, but no chain suck, ghost shifting or anything. AND he could get a good couple of thousand miles out of the set, then he would just buy new all new kit and start again. It worked for him but I don't know about trials bikes, I tend to get about 2weeks riding before something goes wrong and it needs new bits.