Rear Derailleur Woe...
 

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[Closed] Rear Derailleur Woes

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Hey all
So my Sram GX Eagle gave up on me the other day and I can’t source another so bought an NX eagle (brand new).
It’s going on a Scott Spark RC 900 team.
I’ve swapped the two over, got the cable run, it’s taught but I don’t think over tight, if I hold the cable with some pliers I get 11 clicks in both directions. Clip the cable to the cable clamp on the mech and I only get 8 or 9 clicks and I am left with 3 of the smaller cogs not being reached. All looks straight.
Any ideas? I’m going to assume that it’s user and not component, fingers crossed!
Cheers


 
Posted : 13/05/2022 10:39 pm
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Did you clamp it with the cable going over or under the bolt ?

High and low stops / b tension set ?


 
Posted : 13/05/2022 10:42 pm
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Cable going over the bolt. Took a photo but don’t see how to upload it.


 
Posted : 13/05/2022 10:49 pm
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Tried playing with high low screws but I can only move it closer to the wheel, not away, towards the smaller cogs.


 
Posted : 13/05/2022 11:06 pm
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Disconnect the cable. Set the limit screws. Re-connect the cable.


 
Posted : 13/05/2022 11:45 pm
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Definitely sounds like a limit scre problem. I’d remove the cable and start again following the video below:


 
Posted : 13/05/2022 11:55 pm
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Yep limit screw is stopping the mech moving into the 3 smaller/higher gears.


 
Posted : 14/05/2022 12:00 am
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I watched a guest replace a shifter cable once, he set and manually held his mech on the biggest sprocket, added all his clicks onto the shifter then tightened off the cable. I'd never seen that before (rapid ride aside but this was not rapid rise). It took ages and about 4 hands.
You're not doing it that way are you?
That's the only way I can see you loosing the smallest few sprockets if you're working backwards down onto the high stop.
I've have a sram mech loose the smallest sprocket when tightening the shift cable as the bolt rotated the back plate and effectively added extra cable tension like if you shortened the cable with the barrel.
I can't see this taking out more than just one gear though.


 
Posted : 14/05/2022 5:02 am
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I must admit I used to do it that way. No idea why. Maybe it's something that was in maintenance books we learned from before the internet.


 
Posted : 14/05/2022 7:16 am
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I'd suggest not pulling the cable tight (assuming your limit screws are set correctly to begin with), these mechs operate with a little slack in the cable before the first shift.


 
Posted : 14/05/2022 7:55 am
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Thanks every one. Solution was to remove the cable and then set the limit screws as suggested by a couple of folk above. Thank you! 👍👌


 
Posted : 15/05/2022 2:25 pm
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My approach is to screw all the barrel adjuster 3/4 in so there is adjustment both ways plus some extra for any stretch, the shifter in top gear (smallest cog) and then hold the mech over the second smallest cog before applying a bit of tension to the cable and tightening the clamp. When you let go the mech pulls any remaining slack, occasionally it's spot on but normally needs a couple of turns on the barrel adjuster to get it perfect.

Finally, I always wind in the limit screws slightly until it won't shift into top and bottom gear, and then adjust back until it shifts into the full range without fuss, then add an extra turn just to give it a slight ability to over-shift when clagged up. Seen too many mech v spoke incidents to just trust that they are still set correctly!


 
Posted : 15/05/2022 4:39 pm

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