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Former Bike Wrench
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Discussion Starter · #1 ·
I'm stumped

I switched from a 3 x 9 setup with a 48.5mm chainline to an external bearing 2 x 9 crankset with a 51mm chainline. I've used 2 x 9 on my last three bikes so I know how to adjust the front dérailleur stops. But this is my first set of external bearing cranks with a greater chainline.

I got the dérailleur all set but I have to have excessive cable slack in gear 1 to keep the dérailleur from shifting way too far into gear 2. I've never had this problem with my previous 2 x 9 setups...but I've never used an external bearing crankset either.

The derailluer is an X-7, the shifters are X-7, the crankset is a Truvativ FireX

Thoughts? Suggestions?
:confused:
 

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since you've used this setup before, i'm probably telling you something you already know...are you starting the shifter at the bottom, typically granny gear spot, and then going to the typical second gear spot for your big ring? just a thought, maybe try it in the normal 2-3 positions.

also, the chainline does matter a bit. the derailleur is further into it's arc when the chainline is out farther, making the whole adjustment different.

is the cable TOO slack at the bottom, i.e., going to cause a problem?
 

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Former Bike Wrench
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Discussion Starter · #3 ·
Probably not a problem

tskdmz said:
since you've used this setup before, i'm probably telling you something you already know...are you starting the shifter at the bottom, typically granny gear spot, and then going to the typical second gear spot for your big ring? just a thought, maybe try it in the normal 2-3 positions.

also, the chainline does matter a bit. the derailleur is further into it's arc when the chainline is out farther, making the whole adjustment different.

is the cable TOO slack at the bottom, i.e., going to cause a problem?
I did try the 2-3 position and it does work better...since the 1-2 shift pulls more cable than the 2-3 shift. But I figured its the dérailleur as it is in its arc quite a bit more than with my ISIS and Octalink cranksets that has closer to 47.5mm to 48.5mm chainlines.

Its not so slack that it wont work, Its just that the first half of the lever push only takes up the slack before the dérailleur actually moves. I got a Deore front dérailleur off of E-bay for $10 including shipping and I'm going to try it when it arrives. Worst case, it will be no different and I'm only out $10

Thanks:thumbsup:
 

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Asssuming you pulled all the excess slack ouy of the system, there's no harm in having some residual slack. The only concern would be if there were enough slack to disengage from any of the cable guides.

If the cable is passing to the inside (nearer to the pivot) of the pinch bolt, try switching it to the outside, which will effectively lengthen the swingarm and use more cable travel during the shift.

If all else fails, either find a derailleur with a longer swingarm, or adapt to the extra lever travel when shifting.
 

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Former Bike Wrench
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Discussion Starter · #5 ·
Just as a follow up, I received and installed the Deore front dérailleur today and everything works perfect now. I've been a SRAM fan for many years, but it looks like the X-7 front dérailleur is not compatible with a 51mm chainline...the pisser is, its a Truvativ (ie SRAM) crankset!!!
 
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