rear derailleur shifting problem

I had a 10 speed Centuar medium cage derailleur working perfectly for
one year until a stick got caught in it during a 4 day trail ride and
snapped it completely off at the bolt. The dropout was realigned by
an experienced wrench/framebuilder and a 10 speed 105 derailleur (I
was in the midst of a trip and away from big towns) worked
surprisingly well (adjusted so that the middle of the cassette worked
great and just OK at either end). After the trip I installed a new
Centaur RD but it will not hold onto the 2nd and 3rd largest cogs (it
autoshifts down to the next smallest cog). Cable tension is adjusted
perfectly elsewhere along the cassette and it is not a problem on the
biggest rear cog (it's a 13-29 cassette). Over the past 8 years,
anytime shifting hasn't been perfect in the absence of any obvious
reasons, a new spring and post in the shifter have always done the
trick. Didn't help in this case. Only thing left are cables and the
individual cogs but I can't see what could have changed. Any ideas?
-Mike

"mowens61-gmail.com" wrote in message
oups.com...
I had a 10 speed Centuar medium cage derailleur working perfectly for
one year until a stick got caught in it during a 4 day trail ride and
snapped it completely off at the bolt. The dropout was realigned by
an experienced wrench/framebuilder and a 10 speed 105 derailleur (I
was in the midst of a trip and away from big towns) worked
surprisingly well (adjusted so that the middle of the cassette worked
great and just OK at either end). After the trip I installed a new
Centaur RD but it will not hold onto the 2nd and 3rd largest cogs (it
autoshifts down to the next smallest cog). Cable tension is adjusted
perfectly elsewhere along the cassette and it is not a problem on the
biggest rear cog (it's a 13-29 cassette). Over the past 8 years,
anytime shifting hasn't been perfect in the absence of any obvious
reasons, a new spring and post in the shifter have always done the
trick. Didn't help in this case. Only thing left are cables and the
individual cogs but I can't see what could have changed. Any ideas?
-Mike


It sounds like it needs new detente springs in the shift lever. There wear
out over time, $10 in parts and not too tough to fix yourself. See guide
at www.campyonly.com or Google up some others.

Jeffrey

On May 9, 8:46 am, "mowens61-gmail.com" wrote:
I had a 10 speed Centuar medium cage derailleur working perfectly for
one year until a stick got caught in it during a 4 day trail ride and
snapped it completely off at the bolt. The dropout was realigned by
an experienced wrench/framebuilder and a 10 speed 105 derailleur (I
was in the midst of a trip and away from big towns) worked
surprisingly well (adjusted so that the middle of the cassette worked
great and just OK at either end). After the trip I installed a new
Centaur RD but it will not hold onto the 2nd and 3rd largest cogs (it
autoshifts down to the next smallest cog). Cable tension is adjusted
perfectly elsewhere along the cassette and it is not a problem on the
biggest rear cog (it's a 13-29 cassette). Over the past 8 years,
anytime shifting hasn't been perfect in the absence of any obvious
reasons, a new spring and post in the shifter have always done the
trick. Didn't help in this case. Only thing left are cables and the
individual cogs but I can't see what could have changed. Any ideas?

Lever OVH-new shift springs and perhaps a spring carrier($10)..easy,
no big deal. Don't let anybody sell ya a shift disc, they don't wear
out. If you send it to me I'll turn it around in one day-$35 for labor
to completely take apart, relube, springs are $5 per(need 2) and again
the spring carrier if ya need one

Vecchio's
http://www.vecchios.com
-Mike

Qui si parla Campagnolo wrote:
On May 9, 8:46 am, "mowens61-gmail.com" wrote:
I had a 10 speed Centuar medium cage derailleur working perfectly for
one year until a stick got caught in it during a 4 day trail ride and
snapped it completely off at the bolt. The dropout was realigned by
an experienced wrench/framebuilder and a 10 speed 105 derailleur (I
was in the midst of a trip and away from big towns) worked
surprisingly well (adjusted so that the middle of the cassette worked
great and just OK at either end). After the trip I installed a new
Centaur RD but it will not hold onto the 2nd and 3rd largest cogs (it
autoshifts down to the next smallest cog). Cable tension is adjusted
perfectly elsewhere along the cassette and it is not a problem on the
biggest rear cog (it's a 13-29 cassette). Over the past 8 years,
anytime shifting hasn't been perfect in the absence of any obvious
reasons, a new spring and post in the shifter have always done the
trick. Didn't help in this case. Only thing left are cables and the
individual cogs but I can't see what could have changed. Any ideas?

Lever OVH-new shift springs and perhaps a spring carrier($10)..easy,
no big deal. Don't let anybody sell ya a shift disc, they don't wear
out. If you send it to me I'll turn it around in one day-$35 for labor
to completely take apart, relube, springs are $5 per(need 2) and again
the spring carrier if ya need one

Vecchio's
http://www.vecchios.com
-Mike
I waited to write until I already had the springs replaced ("didn't
help in this case" from original post). What's next on the list?
Thanks.
-MIke

Problem solved.

The Centaur cassette was removed and cleaned after my trip. I knew
that there are different sized spacers - round plastic ones, blue
spacer labeled to go between the 6 and 7 cogs, and three gun metal
gray spacers.

I didn't realize that the gray spacers are of different thicknesses
and go into specific spots (why couldn't they be labeled like the blue
one?). How about this for the spacer pattern (smallest to largest
cog) - 2.4 mm round plastic, 2.4 rp, 2.4 rp, 2.4 gray spacer, 2.55
blue, 2.4 gray, 3.05 gray. Of course it's a slightly different
pattern in a Veloce cassette. I put them in the correct order and all
problems solved.
-Mike