1. when i wanna shift to 2nd gear (2nd biggest cog in the cassette) from 3rd gear... it's trying to skip 2nd gear and just goes on this rattling on trying to fall into gear and chain is sitting on top of 1st gear but not really locking.

2. it won't even shift to the 10th gear now. it just gets stuck on 9th gear and just makes rattling noises.

im playing with the 2 screws (high low screws i believe) right now but im not really familiar with them.

help?

To start...

How is the shifting up/down the cassette in the other gears, 3 thru 9?

Can you shift to the largest cog, notwithstanding the poor shift from 3 to 2?

If you can shift to the largest cog, how is shifting up to 2 and 3?

There really should be no need to adjust the high/low limit screws after the initial derailleur install, with the possible exception if you change cassettes or wheels.

Had your RD been bumped immediately prior to this problem, such as laying the bike down, crash, loading/unloading in vehicle, etc? If shifting is otherwise good in 3 thru 9, you may have a tweaked hanger. Whenever you're performing derailleur adjustments, you want to start with a straight hanger. You can do a visual check from the rear of the bike to see how well the two derailleur pulleys and the cog line up, however 9+ speeds are finicky enough that an alignment tool may be required.

+1, dont mess with the stroke limit screws.

Your LBS can see the problem. drop by..

Go to the park tools website and look up the instructions on derailleur procedure (or Sheldon Brown). The procedure is simple, but you won't get it set up simply playing with the H and L screws.

Slide your housings out of the slotted stops (plenty of videos on YouTube- might as well lube the, up while you have access) and inspect the cables themselves, sometimes a kink in the cable can do this. The kink usually comes from the bike being bumped or packed weird among other bikes in a car or on a bike rack.

For the record, you can set the limit screws pretty close to perfect without the cable (do this with the cable detatched or the housings out of the stops) at all- push the RD with your thumb through the range and adjust the limits to where you can just make it not the high and low.

Also, eyeball the RD hanger alignment, a bend can dramatically impact indexing.

yes, i have switched wheels.


ok... i seem to have fixed the problem with by messing with the high low screw in combination with that barrel adjuster thing. it's shifting good for now but this is just from shifting with the bike upside down (i don't have a workstand) so i dunno if real road shifting will be any different.

i will check that park tools and sheldon brown as well if i still get problems... or i'll swing by my LBS on friday.

thanks.

These do nothing but set how far the RD travels and stops (were it stops) has nothing to do with anything in between.
Remove chain shift lever all the way down (I'd remove cable also at RD) line up jockey wheel with the small cog using the limit screw. Move the RD with your thumb all the way to the big cog adjust limit screw so it lines up with it. Same time locate B screw adjust so you have about 1mm from upper jockey wheel and large cog.
Let RD go turn in any barrel adjusters you have on bike, reinstall cable on RD pulling out slack tighten cable clamp use shift up one gear if it doesn't move turn barrel adjuster CCW so it moves up on gear, shift to next gear, it should go up if its slow turn barrel adjuster CCW a little 1/8 turn or so shift up another gear, it should run all gears good, shift down to a middle cog if you have chain rattle a slight turn go barrel adjuster should remove it.
Now at this point if you have trouble with it still something else is wrong bent hanger worn cable and housing or bent parts someplace that you need to check that you need to see, take it in to someone that can look it over its not a simple adjustment it you fallow the above in order.

You say it seems good for now good on the road adjustments are easy at this point slow shifting up to larger cog turn a barrel adjuster CCW slow shifting down to smaller cogs turn barrel adjuster CW simple these turns are small at this point 1/8 no more than 1/4 could be even small 1/16 if you are picky

You can easily mess up the settings enough that when you shift to the biggest cog, your derailleur's pulley cage catches a spoke. Then the derailleur is mangled, ripped off the frame, and your rear wheel is locked up. Hopefully, you don't crash.

The Park Tool website shows how to start at the beginning, setting the limits correctly, and getting the shifts to work perfectly. It's not hard to do, and it's easy to understand once you've done it the first time.

It's worth knowing so that, in the future, when the shifting starts to be a little off, you can fix it in a few minutes.

^ correct the hi and low need to be set like I mentioned above the only purpose for those are to stop the RD at the limits of travel having them to far out can cause damage make sure they are correct don't assume make sure.

damn. imma go out and try shifting to 1st gear. i did a quick test on our complex but only played with 2nd and 3rd gear.

i did run through all the gears earlier when the bike was upside down and going to 1st gear doesn't seem like a problem.

thanks for the warning though.

ok just did another test.

it shifts fine to and from 1st gear.

i tried with both the big and small crank as well.

i think im safe... for now anyway.

If it shifts fine upside down it should shift fine the right way up. Usually all you might miss is some FD chain rub due to gravity's effect on the chain.