It sounds like the initial slack in the system wasn’t accounted for when the indexing was done. So get the bike onto it’s smallest sprocket, then release the cable. Wind both limit screws fully in. Then ( and I find it’s easier to just manipulate the mech by hand ) wind out the L screw a bit, and pinch the mech open at its joint until it hits the limit. Hold it, and visually look down to see where the jockey wheel is in relation to the sprocket. If it’s not directly under the largest sprocket, release the mech, wind the L screw out a bit more, then repeat, winding the L screw out a quarter of a turn at a time, until the top jockey wheel is pretty much under the large sprocket. Then release the mech and see where the jockey wheel is in relation to the smallest sprocket. If it’s not directly under the smallest sprocket, wind out the H screw gradually, until it is. Now wind your barrel adjuster ( the one on the cable, not the indexing screw on the mech) to the point where it’s got equal amounts of in and out ( clock and counter clockwise) adjustment left on it. Give the cable a little gentle tug, with one hand, pinch the mech open just a tiny bit ( it takes any slack out of the spring ) and whilst holding it under tension, clamp the cable back up, then release your pinch. Spin the cranks, change up the cassette and see where your at. You should be able to get it all the way up the cassette, and without overshooting the large sprocket. If it does overshoot, wind the L screw in a fraction. Hopefully you won’t have any ‘spare clicks’ left either ( if you have, that’s not a massive problem, it’s easily sorted ). Now change down the cassette ( up the gears ) and see how far down you can go. Repeat changing up and down, using the main indexing screw on the mech to get the shifts to match the clicks. If you’re not quite getting the chain over the big sprocket going up, wind the barrel adjuster counter clockwise a little, then try going up and down, repeat until the chain goes onto the biggest sprocket cleanly. Then go all the way down to the smallest sprocket, use the main indexing screw to get the shifts roughly right, and if the chain won’t quite go to the smallest sprocket, give the barrel adjuster a sight turn clockwise until it does. Remember that the cables and ferrules and bits and bobs may need a bit of a run out to settle into position, and that your efforts may need a tweak or two, as you actually ride about. But if you’ve done the initial stuff properly, this will just be tweaks on the barrel adjuster, on the cable.
Your reply doesn't help the OP at all.
