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Former Bike Wrench
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15,976 Posts
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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CHOP!
Joined
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243 Posts
BB spacers?

Hey,

I have the same set up so it should work.

What's your spacer orientation on the GXP BB and what size BB shell do you have?

68mm = 1 spacer on each side

73mm = zero spacers

It might help to set it all up again: take the cable off, set your limits and set your height.

Don't forget that your FD height should be the same as when you had your 3x9 - despite now having only 2 rings.

Good luck man.
 

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Former Bike Wrench
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15,976 Posts
Discussion Starter · #3 ·
What's interesting is that if I set the shifter in 2 and set it up to shift from the granny to the middle ring from 2 to 3 then it seems fine. Its just the 1 to 2 shift where there is a problem. I know it pulls more cable in the 1 to 2 shift so I'm wondering if the X-7 front dérailleur is just not good with a 51mm chainline.

Its weird, I just haven't had this issue before and I used to work on bikes for a living.
 

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CHOP!
Joined
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243 Posts
Yeah, but what's your spacer orientation?
That could have an effect on how far your FD has to move to shift.

X.7 works on all outboard bearing cranks.

So, you're over-shifting from granny to middle right? Even though the cable is quite slack when shifted to the granny? Weird... :madman:

I'm assuming, that your FD cage is set up to just barely not rub when you're in the 34t cog?

Perhaps you want to bury your high limit screw to prevent the FD from pushing your chain into your guard? And check your FD height again?
 

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Former Bike Wrench
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15,976 Posts
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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