Odd front shifter p...
 

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[Closed] Odd front shifter problem

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 PJay
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I bought some second hand 3x10 I-SPec XT M780 shifters to replace some perfectly functional Deores. After endless faffing to fit them to my I-Spec brake levers I ran into a problem. I cabled up the left hand shifter to my front mech. (triple) and it shifts beautifully from the granny to the middle ring and from the middle to the big ring. Dropping from the big ring to the middle is fine but dropping to the granny from the middle just doesn't happen; the shifter clicks and I can see the mech move 1-2mm and stop - cable tension remains high.

The odd thing is, that if I unbolt the cable from the mech, apply some tension by hand and operate the shifter I get the same amount of cable tension/release as expected. The minute it's attached to the mech, it seems to jam dropping to the granny (it's correctly set to 3 speed using the underside switch, I think that the original user ran it on a double).

I've taken the cover over but can't see what's going wrong. Sticking the old Deore back on and everything's dandy again.

Does this sound repairable or do I just write it off as duff and stick with the trusty Deores?


 
Posted : 09/09/2019 1:45 pm
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Strange one so here's a bump for the evening crowd.

What front mech is it? Are you routing the cable the correct side?

Do you have a picture?

Have you used new cables, inner and outer?


 
Posted : 09/09/2019 6:12 pm
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Bizzare, sounds like a front mech issue, but it works with the deore, strange. Did you try finger and thumb release, to be honest the upgrade to XT is more about the rear shifter, with the multi release, anything will do for the front, my mates about to put some unused XT front shifters on ebay tonight one 10sp and one 11sp both i-spec b for £12 each.


 
Posted : 09/09/2019 7:33 pm
 PJay
Posts: 4818
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It's Deore T6000 that's coexisted happily with the Deore shifter. With the XT shifter it behaves as described.

If I unbolt the cable from the mech
I get full cable movement, it's as if the extra pull of the mech is causing something to jam (it's second hand and ran ad a double so perhaps something has worn). The Deore shifters are back on.

Tried to do ot on the cheap & ended up having to buy an I-spec A-B converter to get the shifters to fit now I'm back where I started 🙄 I think I'll stick with the Deores for now.


 
Posted : 09/09/2019 8:07 pm
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If the 1st owner only used positions "outer" & "middle", I suppose there may be dry grease/other kack in there. I'd scoosh it out with some GT85 & see if it improves


 
Posted : 09/09/2019 8:13 pm
 JoeG
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Check and see that the cable end fitting is routed and seated properly in the shifter by removing the cover if possible. I've seen cases where there is a kink near the cable end fitting and it does not seat properly and fouls some part of the mechanism. A new cable seated properly fixed it.


 
Posted : 10/09/2019 1:54 am
 PJay
Posts: 4818
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I soaked the innards with GT85 yesterday without success and tried it with the cover off. The cable end is seated correctly; it's an odd one.

Again, with the cable unbolted from the mech. (but routed through the shifter & inners) & some finger pressure on the cable I can see everything works & I can see the cable head carrier snap around correctly on each click. Once the cable's bolted to the mech. it jams dropping from middle to granny; it's as if the extra force/acceleration from the mech. trying to snap back causes something to jam.

I think that I'll just leave the Deores in place for now a ride.


 
Posted : 10/09/2019 7:15 am
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Is this one of them where it has a 2-3 speed switch neatly hidden on it ? These still allow the click but don't actuate if i recall ?


 
Posted : 10/09/2019 7:21 am
 PJay
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It is and it's set to 3. As above, with just some finger pressure on the cable I get the cable pull/release that I'd expect (and I can see the cable head carrier snap around with the cover off) once it's bolted to the mech. it jams.

I'm beginning to think that something's worn or loose in the innards.


 
Posted : 10/09/2019 7:27 am
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Maybe buy another one. 3x left shifters go for peanuts


 
Posted : 10/09/2019 9:50 am

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