BlackChrome

I have a 3 chainring setup. I just got my bike back from the LBS (new chain & front derailleur cable) and it was shifting great. Then, out of nowhere, it wouldn't drop into the smallest chainring. I looked online and it said to adjust the L-Screw. I did it and it worked. Then, for some unknown stupid reason (temptation, curiosity), I decided to adjust the L and H screws to get the cage closer to the chain (1/16 in., I wanted). I made some adjustments and it was all cool. Then, I can't remember doing anything wrong, but I can't get into the big ring at all and the chain is rubbing on the cage like crazy. I can get the L-Screw adjustment to work okay, but when I try to give the outside a little space with the H-Screw, it doesn't even work. The counter-clockwise turns that the Park Tool Repair website tells me to do don't even move the cage. What should I do?

Sorry for such a long explanation, but I didn't know how else to tell it.

If you have any ideas, put them in this thread cuz' I'm not too worried about screwing it up because I'm gonna take it to the bike shop anyway.

thekorn

Hey,
Adjusting the L and H screw should not move the position of the derailleur cage at rest. Those screws limit the position of the derailleur cage to the far right and far left.
The barrel adjusters, usually on the down tube, adjust tension on the shifter cables and therefore the position of the derailleur at rest. Try adjusting the cable tension. Then adjust the limiting screws so that you can't throw the chain off of the smallest and largest chainrings.
Hope that helps.

BlackChrome

I'll try that. Thanks.

Al1943

When setting the low limit screw the chain must be on the smallest chainring and the largest cassette cog.
When setting the high limit screw the chain must be on the largest chainring and the smallest cassette cog.

Al

'nother

Go to https://sheldonbrown.com/derailer-adjustment.html, start at the very beginning and follow the instructions all the way through.

royalflash

STOP!! --before messing with cable tension try this:

start off with the H and L screws screwed all the way out and check that you can shift to all chainwheels (even though the chain may be pushed too far and come off at each end). Once you have established that you can shift the chain to all chainwheels then adjust the H and L screws in until you can JUST shift to the smallest and largest chainwheels (the chain should of course not now come off). You have to keep shifting backwards and forward to check the adjustment of the H and L screws (you cant just watch the cage and adjust the H and L with the cage at rest)

hope this helps

BlackChrome

I haven't done the cable tension thing yet, so I'll try that.

BlackChrome

I combined the advice of bringing the L and H screws all the way out and the cable tension advice and it seemed to work. I'm gonna throw the bike on my trainer later to see how it shift like that, but on the repair stand, it was pretty decent. I'll let you guys know. Thanks.

BlackChrome

Everything seems to be working great (I put it on the trainer). Thanks a million for the tips.