Tiagra and XT shifting problems

On my Cannondale T800 tourer I have Tiagra 9 speed brifters paired with
an XT rear derailor. My problem is whenever I shift into the 8th cog
(28 tooth) the chain doesn't want to stay put. It wants to climb up
into the 9th cog. I tried using the barrel adjuster to loosen the cable
tension but then the chain starts doing a dance routine where it
doesn't know whether to go up one cog or down one cog. I tried zeroing
out the shifter and recalibrating the shift routine by taking out all
the cable tension using the barrel adjuster and then detaching the
cable. I would then reattach the cable and begin tuning the shifting
in. Damn! It didn't work. I thought maybe I got a defective cassette so
I went out and bought another 11-32 cassette. Damn again! It didn't
change a thing. All the rest of the cogs shift just fine. Only the 8th
position cog is for all intents and purposes out to lunch. Your
insights will be highly appreciated.

"Kenny" wrote:
On my Cannondale T800 tourer I have Tiagra 9 speed brifters paired with
an XT rear derailor. My problem is whenever I shift into the 8th cog
(28 tooth) the chain doesn't want to stay put. It wants to climb up
into the 9th cog. I tried using the barrel adjuster to loosen the cable
tension but then the chain starts doing a dance routine where it
doesn't know whether to go up one cog or down one cog. I tried zeroing
out the shifter and recalibrating the shift routine by taking out all
the cable tension using the barrel adjuster and then detaching the
cable.

Assuming you've got the cable tension set right, check that the cable is
anchored at the proper place on the derailleur (very important!). If still
NG, consider having the alignment of the frame's derailleur hanger checked.

http://www.sheldonbrown.com/derailer-adjustment.html

If you're really stuck, visit your LBS. They should be able to fix this
problem quickly and inexpensovely.

Art Harris

Kenny wrote:
On my Cannondale T800 tourer I have Tiagra 9 speed brifters paired with
an XT rear derailor. My problem is whenever I shift into the 8th cog
(28 tooth) the chain doesn't want to stay put. It wants to climb up
into the 9th cog. I tried using the barrel adjuster to loosen the cable
tension but then the chain starts doing a dance routine where it
doesn't know whether to go up one cog or down one cog. I tried zeroing
out the shifter and recalibrating the shift routine by taking out all
the cable tension using the barrel adjuster and then detaching the
cable. I would then reattach the cable and begin tuning the shifting
in. Damn! It didn't work. I thought maybe I got a defective cassette so
I went out and bought another 11-32 cassette. Damn again! It didn't
change a thing. All the rest of the cogs shift just fine. Only the 8th
position cog is for all intents and purposes out to lunch. Your
insights will be highly appreciated.

Cable underneath the der fixing bolt? under the little plate? Not
somehow thru it or above the bolt?

In article
.com,
"Kenny" wrote:

On my Cannondale T800 tourer I have Tiagra 9 speed brifters paired with
an XT rear derailor. My problem is whenever I shift into the 8th cog
(28 tooth) the chain doesn't want to stay put. It wants to climb up
into the 9th cog. I tried using the barrel adjuster to loosen the cable
tension but then the chain starts doing a dance routine where it
doesn't know whether to go up one cog or down one cog. I tried zeroing
out the shifter and recalibrating the shift routine by taking out all
the cable tension using the barrel adjuster and then detaching the
cable. I would then reattach the cable and begin tuning the shifting
in. Damn! It didn't work. I thought maybe I got a defective cassette so
I went out and bought another 11-32 cassette. Damn again! It didn't
change a thing. All the rest of the cogs shift just fine. Only the 8th
position cog is for all intents and purposes out to lunch. Your
insights will be highly appreciated.

The `B' screw adjustment? This is the screw that sets the
clearance of the jockey pulley from the big cog wheels.
Try moving the derailleur further away from the cogwheels
with this screw.

--
gmscchemist

In article .com,
Kenny wrote:

On my Cannondale T800 tourer I have Tiagra 9 speed brifters paired with
an XT rear derailor. My problem is whenever I shift into the 8th cog
(28 tooth) the chain doesn't want to stay put. It wants to climb up
into the 9th cog. I tried using the barrel adjuster to loosen the cable
tension but then the chain starts doing a dance routine where it
doesn't know whether to go up one cog or down one cog. I tried zeroing
out the shifter and recalibrating the shift routine by taking out all
the cable tension using the barrel adjuster and then detaching the
cable. I would then reattach the cable and begin tuning the shifting
in. Damn! It didn't work. I thought maybe I got a defective cassette so
I went out and bought another 11-32 cassette. Damn again! It didn't
change a thing. All the rest of the cogs shift just fine. Only the 8th
position cog is for all intents and purposes out to lunch. Your
insights will be highly appreciated.


Kenny,

When you swap out the cassette, did you also change the chain??

It's always a good idea to change the chain too. But assuming that you
did swap the chain out with the cassette, I suggest you undo the chain
first and do this..

Once you had undone the chain, look at the derailleur pulleys (upper
and lower jockey wheels) and wiggle these 2 wheels side to side. They
shouldn't have excessive play. If they do, you need to replace these
wheels with genuine XT jockey wheels (these are sealed units). Replace
them together in pairs.. If the jockey wheels are fine, again wiggle
the derailleur cage (hold the lower tip near the lower jockey wheel)
side to side again. Again, the derailleur should not display any
excessive side to side play. If you can wiggle the cage side to side
like a joystick, the pivots on your XT derailleur are worn out. In
this case, replace your derailleur with a new one and this should solve
your problem.

Hope this helps..

David.