# Sram Red RD -- won't shift into largest cog



## mjdwyer23 (Mar 18, 2009)

Hi Folks-
I just got finished swapping my Tarmac over to Red (largest endeavour to date), and I have run into a little snag. First off, everything went on nicely, and the directions were clear, so I am pretty happy! However, I am having one tiny problem with the rear derailleur. When I go to downshift into the largest cog, the chain shifts to the cog then immediately clicks out of it. I set up the limit screws as per the instructions, and the RD shifts great through all of the other gears in both chainrings (symptoms occur in large and small chainrings). Any tips? thanks folks! Happy 7/4!


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## JChasse (Sep 16, 2005)

If you really have the limit screw set properly, then you may need more cable tension. You may also have the indexing off by a click, but it doesn't sound that way...

Try this...with the chain in the small chainring in front, shift into the 2nd largest cog in rear. Then, while pedaling, pull on the bare exposed cable until the der. hits the limit and hold the cable that way (keeping tension on it)...what happens? does it complete the shift? Does it stay there until you let go of the cable?


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## mjdwyer23 (Mar 18, 2009)

Yep - stays there until I release the cable.


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## dcb (Jul 21, 2008)

Try using the barrel adjuster on the RD. I think counter clockwise tightens the cable.


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## StageHand (Dec 27, 2002)

Sounds like the shifter isn't being allowed to finish that last shift. Back the limit screw out in 1/8 turn increments until it sticks. If it takes a half turn or more, then start your derailleur adjustment over again.


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## mjdwyer23 (Mar 18, 2009)

Will do -- thanks!


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## mjdwyer23 (Mar 18, 2009)

One more thing -- is the shift lever on the right hand shifter supposed to be flush with the brake lever or slightly behind it? Thanks again!


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## JChasse (Sep 16, 2005)

if pulling the cable allowed a complete shift, it's not likely the limit screw. you just need more cable tension. try backing out the barrel adjuster as suggested above. 

on edit: although, it may be worth a try to back the limit screw off just a bit, if all of your other shifts are crisp and quiet. Just make sure to don't got too far, allowing the chain to make the leap off that last cog!


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## mjdwyer23 (Mar 18, 2009)

Backed out the adjuster -- it started making the 2nd cog shift to the third. Undo cables and start over?


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## Spunout (Aug 12, 2002)

mjdwyer23 said:


> Backed out the adjuster -- it started making the 2nd cog shift to the third. Undo cables and start over?


You turned it the wrong way.


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## JChasse (Sep 16, 2005)

at this point it couldn't hurt to start over (it's all a learning experience; open a beer and have fun tinkering)

start by shifting the shifter to the smallest cog position (least amount of cable tension), and disconnecting the cable. then screw the barrel adjuster all the way in (clockwise), then back it out 1-1 1/2 turns to give yourself room to move. 

then pull the slack out of the cable - if you have a third hand tool, now's the time to use it - and tighten the cable binder bolt. shift through the cogs to make sure your last shifter "click" gets you up to the biggest cog.

If you want more derailleur tuning info from the John Barnett school of thought, read on. Otherwise, if it’s going to put you to sleep, ignore…

Shift to the big chainring in front and the smallest cog in the rear. While pedaling, using the shifter, shift one click. If all’s well, the chain shifted up a cog. If not, and it stayed where it was (on the smallest cog) you need to re-do the last part to be sure you have all slack out of the cable.

Now that one click has the chain on the 2nd smallest cog (and you're pedaling during all of this, of course), you want to turn the barrel adjuster out (counter-clockwise) until it slightly over-tensions the cable and it starts making noise. if you look carefully, you can see the chain is starting to rub on the 3rd smallest cog. You then just turn the adjuster back in (clockwise) until things get quiet. Then shift up a cog and again make sure it's not rubbing on the next biggest cog. If it is, turn the barrel adjuster in until it's quiet. Repeat a couple more times up through the cogs and you should be good to go at that point. If not, report back here and tell us what’s up…

on edit: this should work on Shimano and Campy rear derailleurs, but i've never owned SRAM stuff. If SRAM is all jacked up and the barrel adjusters work backwards somehow or there's some other weirdness, you're on your own.


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## mjdwyer23 (Mar 18, 2009)

good stuff -- thanks again!


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