rear derailleur/cluster problem

pudster

It is kind of hard to say without more info. It could be just a simple barrel adjustment or it could be that your chain and cassette are wearing out. Maybe first check your chain for wear. Being from Aus. do you have an english tape around? If you do take the zero mark and center it on a chain rivot and put the 12 mark on or near the the rivot that is 12 inches out. If the 12 mark is right on the center of the rivot then you are good. If it is 1/16th of an inch longer then you need to replace the chain and maybe your cassette. Twelve inches of chain is 24 links and if there is 1/16th in. of stretch it is a good time to change it. Hopefully that is not the problem. If not it could just be a cable adjustment at the rear derailleur. Put your chain on the middle ring and the small cassette cog and pedal the bike in a repair stand or something simular where the rear wheel is off the ground. Listen to the rear derailleur for chain noise, like it is not quite in gear and go through all the cogs in back. If you hear noise that sounds like clicking noise turn the barrel adjuster counter clockwise as facing the rear of the bike. Most of the time it is a tightening job of the adjuster. If you have put on new cables or crashed on your derailleur it could be a bent der. hanger. Maybe take it to a shop to have it aligned properly but take it to a good shop. These are a couple of things to check. Check all your gears in back on all chainrings up front and listen for chain noise that sounds like it wants to change gears on you. And turn the barrel adjuster in back to clean up the noise. Don't turn the barrel adjuster more than a half a turn and should be good with less than a quarter turn. Hope this helps you out, it is not too hard to do, it just sounds bad.