Originally Posted by
Liveon2wheels
I definitely need to change cassette and chain ring and, if a new chain will help with maintenance, then that too but are there any simple visual checks I can do with the derailleurs to check that they are ok before I buy more? I'll take everything apart and give them a clean when I replace the cassette and ring and decide then if I'm going to change them.
Your first error might be assuming that you definitely need to change these things. Why are you so sure that they need changing? You might need to step back on your trouble shooting. First of all, do you know how to adjust your cable tension and otherwise tune up your derailleurs? You should tune up your derailleurs before you start changing stuff. You might need to change out your chain. Do you know how to check for chain wear? If it is really worn, you might need to change out the cassette but unlikely the chain rings. Be sure to keep your chain clean and lubed. It should last more than 1000 miles.
Park Tool website has good instructions on adjusting your derailleurs. It will also show you how to check for chain wear.