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Discussion Starter · #1 ·
Per the thread title, I have a Sram Rival rear derailleur that will not shift down to the two lowest cogs (on my gravel bike). If you shift down, and give it some time, it will eventually work it's way down there. I thought it was cassette/chain issue, so both of those have been changed, as has the shifter cable. You can back all of the tension off the cable and it still won't shift down, the high limit screw is backed out so far that it's not even touching the stop. B-screw is adjusted per Sram specs.

You can shift down, and give the derailleur a little nudge and it'll finally shift down, but otherwise, no. Also, (and importantly) I checked the derailleur hanger and it's in adjustment.

I'm stumped. It almost feels like the return spring on the derailleur has lost it's...spring. I've cleaned and lubed (the pivot points) the heck out of the derailleur, basically everything but actually taking it all the way apart. In all my years of wrenching, I've never had a derailleur just quit working. Any ideas what my next move should be? Thanks!
 

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I'm a new rider on a nicer bike, and being a risk-taker, I've had my fair share of falls. After awhile, the derailleur just stopped being adjustable, and no amount of adjustments could get it to shift properly. I got it to the point where it works, but like the original poster, lose a couple of gears, depending on how I adjusted it. So I just bought a new one and all of the problems went away.

I may move up to the AXS GX Eagle, but I'm waiting to see if they're durable and easier to adjust if out of whack.
 

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Per the thread title, I have a Sram Rival rear derailleur that will not shift down to the two lowest cogs (on my gravel bike). If you shift down, and give it some time, it will eventually work it's way down there. I thought it was cassette/chain issue, so both of those have been changed, as has the shifter cable. You can back all of the tension off the cable and it still won't shift down, the high limit screw is backed out so far that it's not even touching the stop. B-screw is adjusted per Sram specs.

You can shift down, and give the derailleur a little nudge and it'll finally shift down, but otherwise, no. Also, (and importantly) I checked the derailleur hanger and it's in adjustment.

I'm stumped. It almost feels like the return spring on the derailleur has lost it's...spring. I've cleaned and lubed (the pivot points) the heck out of the derailleur, basically everything but actually taking it all the way apart. In all my years of wrenching, I've never had a derailleur just quit working. Any ideas what my next move should be? Thanks!
Can you force the derailleur into the proper high gear (smallest cog) position by hand? If its a worn spring you should still be able to push it into place, or else maybe something is jammed inside the RD? Sounds like a weird one.
 

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Discussion Starter · #7 ·
Can you force the derailleur into the proper high gear (smallest cog) position by hand? If its a worn spring you should still be able to push it into place, or else maybe something is jammed inside the RD? Sounds like a weird one.
Yea, you can move the derailleur by hand with just a light nudge. It's not like it's movement is impeded, it takes very little to pull it into place. Actually, when you're riding, it'll eventually shift down it just takes some vibration to get it to move. Honestly, it just feels like the return spring doesn't have enough tension to pull it back into place. I guess I've got a new derailleur in my future. Just wanted to makes sure I'd checked-off all the boxes before I pulled the trigger. Thanks!
 

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last two is odd

last one could be b-screw regardless of spec, unscrew it some more

but two cogs, likely not b-screw related
 

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I'm a new rider on a nicer bike, and being a risk-taker, I've had my fair share of falls. After awhile, the derailleur just stopped being adjustable, and no amount of adjustments could get it to shift properly. I got it to the point where it works, but like the original poster, lose a couple of gears, depending on how I adjusted it. So I just bought a new one and all of the problems went away.

I may move up to the AXS GX Eagle, but I'm waiting to see if they're durable and easier to adjust if out of whack.
User error. I have beat the **** out of mine and still worked fine, just occasionally had to straighten it back out.
 

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Discussion Starter · #11 ·
Does it move freely with the cable removed? When was the last time you replaced inner and outer cables?
Has a new inner cable, previous owner had just replaced the housings less than a year ago. Cable moves freely through the housing, no resistance at all. Even if you take all of the tension off the cable (where the cable is just dangling) it still won't move all the way down, you have to tap it lightly to get it to move down further.
 

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Yea, you can move the derailleur by hand with just a light nudge. It's not like it's movement is impeded, it takes very little to pull it into place. Actually, when you're riding, it'll eventually shift down it just takes some vibration to get it to move. Honestly, it just feels like the return spring doesn't have enough tension to pull it back into place. I guess I've got a new derailleur in my future. Just wanted to makes sure I'd checked-off all the boxes before I pulled the trigger. Thanks!
It sounds like the spring. One idea to check is: lube the derailleur parallelogram pivots. I have never done this or heard of it in fact but its one more box to check i suppose.
 

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Discussion Starter · #14 ·
Okay this is an old thread, but I thought I'd offer an update. I'd accepted the fact that I just had some worn components and that some new parts were in order. Luckily, I hadn't ordered anything yet. In my 22 years of bike wrenching, I've never experienced this one. So I had my gravel bike in the stand last night getting it ready for a ride on Sunday. I was cleaning up the drivetrain and I started running the bike through the gears as. I noticed that not only was the bike not shifting down to the smallest cog, it wasn't shifting down at all. Then I focused my attention on the cable itself.

I realized that from the BB to the dropout, the cable still had tension. From the BB up to the shifter, no tension. Then it hit me. I flipped the bike over, and there it was. The cable guide was packed with dirt/grit. I pulled the cable out and took the guide off. After cleaning it, I realized that the cable had worn a groove into it. This would explain the extra little resistance I was getting that wouldn't let the derailleur drop all the way down. The wear was gradual (as was the cable resistance), but once it dug down deep enough into the guide it was over.
 
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