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1. Ax3M4n - Member

   First the details:-
   Deore XT Rear Mech
   Deore XT Chain Rings
   SLX Front Mech
   SLX Shifters
   9 Speed Cassette Unknown
   Bike: Trek Fuel Ex 8

   As implied by title, I am having a problem with ghost shifting or delayed shifting. Rear gears shift without me wanting to or gears don't shift (until later) when I do.

   Thing is I have had it in to LBS twice. When it's up on the stand, they've twiddled and fettled and said:-

   "There you go, all works Fine"
   "Cool - what was wrong with it?"
   "Nothing really, just needed adjusting"
   "How much will that be?"
   "Nothing, it only takes a minute"
   "Cool!! What if it happens again?"
   "Should be OK, but just bring it back if it isn't"

   Very nice service - but within "a ride" of having it sorted it starts again. I don't want to be a burden on my LBS, but I also want to get it fixed.

   What advice can you offer?

   Posted 1 year ago #
2. anotherdeadhero - Member

   Are your outers long enough? Watch them as you compress the suspension.

   Posted 1 year ago #
3. Mackem - Member

   exorcism or ghostbusters

   Posted 1 year ago #
4. fasthaggis - Member

   Maybe need to check all the ends of the outers ,you may have a collapsing nipple. Now you don't want one of those ,do you sir?

   Posted 1 year ago #
5. bigyinn - Member

   Are you on a full sus bike or hardtail?
   If hardtail, its unlikely to be outers too short.
   If full sus, i'd go for the outers too short.

   Posted 1 year ago #
6. titusrider - Member

   put on workstand
   take out/empty air from rear shock
   pedal bike
   move swingarm up and down
   if it jumps gears you know that you have a suspension based ghoast shift

   you can then change the routing or length of gear cable outers to remedy

   Posted 1 year ago #
7. ballsofcottonwool - Member

   8speed + SRAM 1:1 rear mech and shifters

   Posted 1 year ago #
8. Hob Nob - Member

   In my experience, suspension based ghost shift.

   Posted 1 year ago #
9. Ax3M4n - Member

   The Outers I assume is the plastic sheathing?

   Anyways, there is a short length of sheathing from the rear mech up to the seat stay where it goes into a metal gromet type thingy at which point it's just bare cable, then back into sheathing at the top of the seat stay. Same thing happens under the top tube.

   Which section is likely to be the "Short Outer" causing the problem?

   I was also wondering about getting the whole cable sheathed (possibly Gore or something) - but what about metal nipple/gromet things - they are welded to the frame. Also would it even be a solution to do this?

   If it is rear suspension related - does that mean there's nothing I can do about it (i.e. common problem on all rear suspensions?)

   Posted 1 year ago #
10. 5AM - Member

    Possibly the outer being too short underneath the bottom bracket.

    As the suspension compresses the shifter cable gets pulled tighter around the BB as it's acting as the pivot point, hence the ghost shift.

    Definitely a possible as I've had the same thing before myself.

    Posted 1 year ago #
11. iainfrancis - Member

    Why not just replace the cable anyway? And if it still does it at least it's one thing you know isn't causing it.

    Posted 1 year ago #
12. Ax3M4n - Member

    Hmmmm.... not sure I want to cough up dosh just to find out if it's the problem or not.

    The cable doesn't go under BB, it runs up the seat stay and under top tube. When suspension compresses, the loop does flex, but I would think it's supposed to.

    What about gear cable going in and out of sheathing? The cable is exposed up the seat stay and under the top tube. There are little rubber boots where it runs in/out of the sheathing which are clipped into metal "eyes" welded to the frame. Is full sheathing an option? Or even desirable?

    Posted 1 year ago #
13. Ax3M4n - Member

    Thanks for your replies people.

    I'll ask the LBS to look at this and replace if necessary.

    Cheers.

    Posted 1 year ago #

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