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Old 05-14-12, 08:35 PM   #1
ParkingTheBus
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How do I fix ghost shifting? Can I still ride?

Me and my friends are going for a ride in a couple of days. My road bike started ghost shifting a couple days ago, and I have no clue how to get it fixed. It's the first ride of the year so I want to go, plus it's only about 30km.

Can I still ride my bike? Is it advisable not to? I'll send it to the bike shop right after the ride. Can I fix it myself?
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Old 05-14-12, 08:54 PM   #2
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Is it happening on the front or rear? I had something like that happening recently on the front and the problem was a warped chainring. It was easy to identify. I just looked down and could see the chainline waving back and forth against the FD cage.
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Old 05-14-12, 10:32 PM   #3
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Describe the ghost shifting in more detail such as: front or rear? one gear at a time or multiple jump? does it affect all gears or just certain ones? does it happen under certain conditions such as when hitting bumps or rough patches? Type of shifters and derailleurs?
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Old 05-14-12, 11:18 PM   #4
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If it's the rear, is it making noise when you ride? My guess is you need to adjust the rear derailleur to line it back up with the cassette. More info please!
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Old 05-14-12, 11:45 PM   #5
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Sorry guys, but the problem is in the rear. I believe it jumps by one gear at a time, but a couple times I swore it jumped by a couple. I tried twisting the barrel adjustor and I will test it out tomorrow.
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Old 05-15-12, 05:11 AM   #6
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"I tried twisting the barrel adjustor and I will test it out tomorrow." Randomly fiddling with adjustments will get you nowhere unless you are lucky. If you don't feel like trusting to luck, adjust your derailleur in a methodical fashion: http://www.parktool.com/blog/repair-...nts-derailleur Bikes do not usually just start mis-behaving all of a sudden. Did your bike get dropped or hit? If your derailleur or its hanger got bent you will have problems until this is resolved.
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Old 05-15-12, 08:16 AM   #7
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Goofy indexing? I always put the alignment tool on the derailleur hanger,
1st.

Bike Shop tool gets it square to the wheel.
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Old 05-15-12, 08:30 AM   #8
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Did the problem start suddenly, or progressively get worse over time until if finally got this bad?

The answer is important because a sudden onset points to the hanger tab having gotten bent in slightly, while a gradual worsening points to an adjustment or a sticky cable.

If the hanger isn't bent in, you can probably ride the bike as long as it isn't so bad as to make it impossible. But if it is the hanger, then don't ride the bike because you're at risk of overshifting the chain or RD into the wheel.

That's all I can tell you based on the limited description in your post. For anyone to help with an actual solution, we'd need much more details, but since you're willing to go to the LBS anyway, you're only decision now is whether it's safe to ride.
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Old 05-15-12, 11:32 AM   #9
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Quote:
Originally Posted by ParkingTheBus View Post
Me and my friends are going for a ride in a couple of days. My road bike started ghost shifting a couple days ago, and I have no clue how to get it fixed. It's the first ride of the year so I want to go, plus it's only about 30km.

Can I still ride my bike? Is it advisable not to? I'll send it to the bike shop right after the ride. Can I fix it myself?
check the threaded derailleur mounting bolt. if loose, the derailleur won't stay oriented in the correct plane, particularly when extended.

do you have a tight link in your chain? watch it carefully as you slowly backpedal through the derailleur pulleys.

start the adjustment process again from scratch as per the parktool link provided.
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Old 05-15-12, 06:43 PM   #10
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If you have BB cable guides, check to see if the cable is lubed where it passes through. Occasionally a cable with high guide friction will cause shifting when the frame flexes (like stomping it up a hill). Long shot, but easy to check and fix.

-G
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