Ghost Shifting from Hell

[TwoLeggedHorse]

Getting straight to the point, my bike is ghost shifting. The shifters/derailleurs are Shimano XT. Either on a straight away or bumpy incline, the chain on my bike tends to shift on its own from one high gear to one low . I've tried dialing the rear shifter, but it hasn't worked. Then I attempted to tweak the high and low settings on the rear derailleur, but that hasn't work. I'm at a point in my life I just want the buy a whole new derailleur.

Any advice to solve my problems would be great. Thanks guys.

Twoleggedhorse

[KeepsWhatHappens]

Did you recently replace any part of your drive chain such as your chain?

Sometimes if you replace one part of your drivetrain and you've waited a while to make that change the act of putting a new part (such as a chain) into the "old system" can cause skipping or ghose shifting.

Or is your deraillerur bent?

KeepsWhatHappens

[bjammin]

Install a new rear drr. cable and make sure the length of housing that runs from the chainstay to the drr. is not too short. If it is, it will cause the drr. to move ever so slightly as the suspension cycles resulting in shifting havoc.


If this doesn't work...throw a rock at it.

[genusmtbkr5]

Originally Posted by KeepsWhatHappens

Did you recently replace any part of your drive chain such as your chain?
KeepsWhatHappens

I think he just bought the bike at the last Path parking lot sale which wasn't that long ago.

[jeffj]

Assuming the cables slide easily in the housings and shifters work freely...

- Cable adjuster on rear derailleur backed out all the way from derailleur

- Cable housings too short/tight, especially those at the RD or near the BB

- Bent hanger

- Bent RD

- Loose cassette "nut"

- Download the derailleur installation instructions from Shimano's website and follow the adjustment instructions. It's pretty straightforward to set the stop points and how to line up the RD pulley to the cassette.

That's where I would start.

[Abui]

Originally Posted by TwoLeggedHorse

Getting straight to the point, my bike is ghost shifting. The shifters/derailleurs are Shimano XT. Either on a straight away or bumpy incline, the chain on my bike tends to shift on its own from one high gear to one low . I've tried dialing the rear shifter, but it hasn't worked. Then I attempted to tweak the high and low settings on the rear derailleur, but that hasn't work. I'm at a point in my life I just want the buy a whole new derailleur.

Any advice to solve my problems would be great. Thanks guys.

Twoleggedhorse

High and low settings on the derailleur only act as stops.

(When you say it always ghost shifts from high gear to low gear you must mean from a smaller cog to a larger cog, right?)

You need to adjust the cable tension. Put the bike in a stand or have someone hold the rear wheel off the ground. Turn the cranks and shift through all the gears. Shift into 2nd. Turn the barrel adjuster on the derailleur until the chain starts to skip up to 3rd gear. Back off a little. End of quick fix.

edit - 2nd here means second smallest cog, etc.

[genusmtbkr5]

Originally Posted by Caveman

High and low settings on the derailleur only act as stops.

(When you say it always ghost shifts from high gear to low gear you must mean from a smaller cog to a larger cog, right?)

You need to adjust the cable tension. Put the bike in a stand or have someone hold the rear wheel off the ground. Turn the cranks and shift through all the gears. Shift into 2nd. Turn the barrel adjuster on the derailleur until the chain starts to skip up to 3rd gear. Back off a little. End of quick fix.

I agree with caveman. The bike is only a couple of months old. Unless you crashed and bent something, it's probably just cable tension.

[pollu_sean]

2 things, make sure the cassette is secure, a loose cassette will cause havoc on shifting. second, make sure cables are lubed and they slide easily in the housing. i had recently found that whoever cut the housing for my cables pinched one end causing the cable to bind there...fixed easily by pulling the nipple off the offending end and widening the hole a bit. problem solved.

[Pain Freak]

This can be one of those nerve wracking problems that drive you nuts!

I had similar issues with one of my bikes. I have always been able to dial my derailuers in without to much problem, but this last time took a lot of work. I finally gave up and went back to my LBS. The owner who I trust more then anyone to work on my bike took a long look at it and suggested we change the middle ring. We did and problem was solved, but I fought this thing for two months before this finally solved the problem. I'd say take it to the LBS and let a competant wrench take a look at it.

[coldbrews]

I was having the same problem with my new bike 2 mos. ago when I bought it. I took it in 3 different times one right after the other, each time they fixed it they told me it was the cable stretching. Finally after the third visit I havent had any more problems.

I would give Cavemans suggestion a shot.

[thephat]

Originally Posted by genusmtbkr5

I think he just bought the bike at the last Path parking lot sale which wasn't that long ago.

Have we had a shot at this one yet? It sounds like it may be covered under our free post sale sevices.

[Shu]

Myself and 4 others all bought Hecklers at the same time and from the same shop....1 of the bikes has had this problem from the 1st ride....it has been in to 3 different shops inc the shop that the bikes were purchasd from 2x's(no warrenty attempt to fix)...NOBODY has been able to fix the problem yet ALL claim the problem is solved..it happens on flats...climbs...but can also be intermitnant....won't do it for the 1st part of the ride but constantly on the 2nd half AND vice versa..ALL the tips listed above have been tried by myself...bike owner...LBS...Look out Path it's on it's way to you this week....

[mytrustysteed]

Originally Posted by bjammin

If this doesn't work...throw a rock at it.

This is my method for fixing EVERYTHING!

[Abui]

Bike with problem - low normal derailleur?

[DeeZee]

Originally Posted by Shu

Myself and 4 others all bought Hecklers at the same time and from the same shop....1 of the bikes has had this problem from the 1st ride....it has been in to 3 different shops inc the shop that the bikes were purchasd from 2x's(no warrenty attempt to fix)...NOBODY has been able to fix the problem yet ALL claim the problem is solved..it happens on flats...climbs...but can also be intermitnant....won't do it for the 1st part of the ride but constantly on the 2nd half AND vice versa..ALL the tips listed above have been tried by myself...bike owner...LBS...Look out Path it's on it's way to you this week....

Make sure everything is tight on the frame. A flexy frame can cause shifting fits.


[SIZE=1]ps:[/SIZE]

[SIZE=1]Warning smart a$$ comment coming[/SIZE]

[SIZE=4]GO SINGLE SPEED!!!!!!!!![/SIZE]

[Shu]

We have gone over EVERY bolt/nut/screw/cog/chainring...anything that can be tightened has been....
ThePhat the bike is a black Heckler owned/riding by ClDrnkr(Rob)....I'm telling him to talk to you or Sarah b/c you to or the only names I know from the shop...

[Wrecker]

Hmmm, Halloween, Ghost shifting...coincidence? Someone had to say it

Take it to the Path, always more productive to have them work on a bike than to throw a rock at it. If it is a new bike, could be cable stretch, in which case, follow Caveman's advice. But then, what the hell do I know?

[DirtRider]

Take it to your LBS... i read somewhere on STR of a few good ones... i had a very similar issue and took it to my LBS. they took it back behind the black curtain and a few minutes later it was shifting and holding gears perfectly. i did see some smoke and heard a few curse words from behind the curtain. They told me that was standard protacol in fixing ghost shifting.

[92se-r]

The problem is that it is a Shimano. Convert to SRAM and say bye to ghost shifting. Worked for me and never looked back. I was always fumbling around with my XT's. After the initial adjustment on the X series, you literally never have to touch it again.