Rear derailleur initial cable tension

Josh Hassol said:

Good morning, all -

When installing a new rear derailleur, how tightly should the cable be
pulled, prior to any STI adjustments? I just installed a rear
derailleur, and I set the shifter to the highest gear (smallest cog),
and then pulled the cable snug, but not tight. I'm having trouble
getting the indexing to work smoothly and accurately in both
directions, and I suspect the cable tension is wrong, but no amount of
tweaking (with the barrel adjuster) seems to fix it. Its a 105 9-speed
derailleur, and a Dura-Ace 9-speed STI shifter.

Any advice would be appreciated.

Josh

make sure the pulley is aligned with the smallest cog first. Pull the
cable tight. Shift once and ensure the pulley is aligned with the next
cog bigger, adjust with barrel adjust, shift again and check each
time....at the biggest, ensure the limit screw will not allow the chain
to go into the spokes.

Josh Hassol said:

Good morning, all -

When installing a new rear derailleur, how tightly should the cable be
pulled, prior to any STI adjustments? I just installed a rear
derailleur, and I set the shifter to the highest gear (smallest cog),
and then pulled the cable snug, but not tight. I'm having trouble
getting the indexing to work smoothly and accurately in both
directions, and I suspect the cable tension is wrong, but no amount of
tweaking (with the barrel adjuster) seems to fix it. Its a 105 9-speed
derailleur, and a Dura-Ace 9-speed STI shifter.

Any advice would be appreciated.

Josh

I also use new inner wire and housing with a new rear der and make sure
the under BB guide is clean.

Qui si parla Campagnolo said:

make sure the pulley is aligned with the smallest cog first. Pull the
cable tight. Shift once and ensure the pulley is aligned with the next
cog bigger, adjust with barrel adjust, shift again and check each
time....at the biggest, ensure the limit screw will not allow the chain
to go into the spokes.

Thanks. How is the initial alignment with the smallest cog achieved,
prior to pulling the cable tight?

Qui si parla Campagnolo said:

I also use new inner wire and housing with a new rear der and make sure
the under BB guide is clean.

Yup! Did that. Thanks.

"Josh Hassol" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Good morning, all -

When installing a new rear derailleur, how tightly should the cable be
pulled, prior to any STI adjustments? I just installed a rear
derailleur, and I set the shifter to the highest gear (smallest cog),
and then pulled the cable snug, but not tight. I'm having trouble
getting the indexing to work smoothly and accurately in both
directions, and I suspect the cable tension is wrong, but no amount of
tweaking (with the barrel adjuster) seems to fix it. Its a 105 9-speed
derailleur, and a Dura-Ace 9-speed STI shifter.

Any advice would be appreciated.

Bolt on the new rear derailleur (check derailleur hanger),
Shift to highest gear (smallest cog),
Adjust (high) limit screw so that the upper pulley is straight under the
smallest cog,
Screw the barrel adjuster or adjustscrew at the back of the derailleur
almost in,
Install (new) inner wire and pull it tight and tighten the bolt,
Unscrew (high) limit screw a little, you will see that the upper pulley will
move a little outward,
Adjust with the barrel adjuster or adjust screw (preferred) at the back of
derailleur so that the upper pulley is straight under the smallest cog
again,
Put on the chain and shift up and down. Only a little tweaking will be
necesarry if the derailleur hanger is straight, the inner wire moves
smoothly and the upper pulley doesn't have to much play.

Lou

Lou

Josh Hassol said:

Good morning, all -

When installing a new rear derailleur, how tightly should the cable be
pulled, prior to any STI adjustments? I just installed a rear
derailleur, and I set the shifter to the highest gear (smallest cog),
and then pulled the cable snug, but not tight. I'm having trouble
getting the indexing to work smoothly and accurately in both
directions, and I suspect the cable tension is wrong, but no amount of
tweaking (with the barrel adjuster) seems to fix it. Its a 105 9-speed
derailleur, and a Dura-Ace 9-speed STI shifter.

Any advice would be appreciated.

IMO, the cable is probably dragging just a bit. I'd replace it and
try again. Use *really good* cables on 9s setups; motion transmission
accuracy is important with these.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Josh Hassol said:

I'm having trouble
getting the indexing to work smoothly and accurately in both
directions, and I suspect the cable tension is wrong, but no amount of
tweaking (with the barrel adjuster) seems to fix it. Its a 105 9-speed
derailleur, and a Dura-Ace 9-speed STI shifter.

Perhaps the routing of the cable at the attachment bolt is incorrect.
It goes under the bolt and not above or through the clamp.

Josh Hassol said:

Good morning, all -

When installing a new rear derailleur, how tightly should the cable be
pulled, prior to any STI adjustments? I just installed a rear
derailleur, and I set the shifter to the highest gear (smallest cog),
and then pulled the cable snug, but not tight. I'm having trouble
getting the indexing to work smoothly and accurately in both
directions, and I suspect the cable tension is wrong, but no amount of
tweaking (with the barrel adjuster) seems to fix it. Its a 105
9-speed derailleur, and a Dura-Ace 9-speed STI shifter.

Any advice would be appreciated.

Josh

I find that the smallest cog tends to cause the cable to have very little
tension.
--
Phil, Squid-in-Training

Josh Hassol said:

Qui si parla Campagnolo said:

make sure the pulley is aligned with the smallest cog first. Pull the
cable tight. Shift once and ensure the pulley is aligned with the next
cog bigger, adjust with barrel adjust, shift again and check each
time....at the biggest, ensure the limit screw will not allow the chain
to go into the spokes.

Thanks. How is the initial alignment with the smallest cog achieved,
prior to pulling the cable tight?

By eyeball and moving the der right or left with the limit screw. You
can also slowly rotate the crank and hear if the chain is 'tickling'
the next cog bigger, than move it an RCH the other direction.

Qui si parla Campagnolo said:

Quoted message said:

By eyeball and moving the der right or left with the limit screw. You
can also slowly rotate the crank and hear if the chain is 'tickling'
the next cog bigger, than move it an RCH the other direction.

Thanks. I went to the Shimano site and downloaded their installation
instructions which, in this case, turn out to be very informative and
fairly well-written.

- Josh

Qui si parla Campagnolo said:

move it an RCH the other direction.

That's a mighty fine adjustment! ;^)

Quoted message said:

I find that the smallest cog tends to cause the cable to have very little
tension.

true!!! - pulling cable tight with vice grips tends to overcome this
problem-on a friction shifter(also set tight for climatic change) tight
to the point of yanking shifter from stem

Michael Dart said:

Qui si parla Campagnolo said:

move it an RCH the other direction.

That's a mighty fine adjustment! ;^)

Thinnest 'natural' thing there is..

Qui si parla Campagnolo said:

Michael Dart said:

Qui si parla Campagnolo said:

move it an RCH the other direction.

That's a mighty fine adjustment! ;^)

Thinnest 'natural' thing there is..

What's RCH? Royal Cat House?

--
"All my time I spent in heaven
Revelries of dance and wine
Waking to the sound of laughter
Up I'd rise and kiss the sky" - The Mekons

It can be tough to get the last bit of slack out of the cable on the
rear derailer by pulling alone. One trick to ensure that the cable is
tight is to push the derailer in a few millimeters when you make the
final pull on the cable before tightening the screw. When you release
the pressure on the derailer, it will take the last bit of slack out of
the cable before it hits the limit stop. You will then have to make
fewer corrections with the adjuster barrel to get things perfectly
aligned.

http://history.nasa.gov/EP-95/acronym.htm
ha ha ha ha!
ASK>>> tea??

G.T. said:

Qui si parla Campagnolo said:

Michael Dart said:

Qui si parla Campagnolo wrote:

> move it an RCH the other direction.

That's a mighty fine adjustment! ;^)

Thinnest 'natural' thing there is..

What's RCH? Royal Cat House?

Some of that acronym is not fit for a family newsgroup. I'd bet you
don't have one, but you might find one at home.

--
Dave
dvt at psu dot edu

dvt said:

G.T. wrote:

Quoted message said:

Quoted message said:

What's RCH? Royal Cat House?

Quoted message said:

Some of that acronym is not fit for a family newsgroup. I'd bet you
don't have one, but you might find one at home.

So what's the 'R'?

Bill "splitting hairs" S.

In article <[email hidden]>,

Sorni said:

dvt said:

G.T. wrote:

Quoted message said:

Quoted message said:

What's RCH? Royal Cat House?

Quoted message said:

Some of that acronym is not fit for a family newsgroup. I'd bet you
don't have one, but you might find one at home.

So what's the 'R'?

Oh, allright. crimson, scarlet, vermillion, carmine,
maroon, burgundy, madder, blush, russet, flame.

--
Michael Press