Diminished shift quality after switching to closer-spaced cassette...

Hi all,

I have an mtb with a SRAM X0 rear der and a SRAM twist shifter. I was
previously running a 9-speed 11-34 SRAM cassette (has a red spider,
don't know the model) with a triple front 42-32-22.

To give myself more usable gears (I never used the granny with the
11-34), I switched the rear cassette to a SRAM PG970 road cassette,
12-26. Still using the triple front. Chain is well used but still
within normal range according to my tool.

Surprisingly, shift quality is noticeably poorer after changing the
cassette. The chain doesn't hesitate, but there is a noticeable thunk
(more a feeling than a sound). This is distracting when shifting
under load. The derailleur is properly adjusted.

Anything I can do to remedy this? Would a different cassette yield
better shifting? Any other tips? I like close spacing in back and
would prefer to keep my 3x9 setup.

On Apr 28, 10:25*am, Dave wrote:
Hi all,

I have an mtb with a SRAM X0 rear der and a SRAM twist shifter. *I was
previously running a 9-speed 11-34 SRAM cassette (has a red spider,
don't know the model) with a triple front 42-32-22.

To give myself more usable gears (I never used the granny with the
11-34), I switched the rear cassette to a SRAM PG970 road cassette,
12-26. *Still using the triple front. *Chain is well used but still
within normal range according to my tool.

Surprisingly, shift quality is noticeably poorer after changing the
cassette. *The chain doesn't hesitate, but there is a noticeable thunk
(more a feeling than a sound). *This is distracting when shifting
under load. *The derailleur is properly adjusted.

Anything I can do to remedy this? *Would a different cassette yield
better shifting? *Any other tips? *I like close spacing in back and
would prefer to keep my 3x9 setup.

Wide range derailleurs never feel as precise on narrow range
cassettes, generally because they are pushing around so much chain.
Assuming that your chain is still in good shape (never a given,
notwithstanding measurement tool -- try using a steel ruler instead to
see if the two agree), try shortening the chain. Also make sure that
your cables are well adjusted and lubricated. A bent derailleur hanger
also makes more of a difference in the small, closely spaced gears,
IMO. -- Jay Beattie.

On Apr 28, 10:56*am, Jay Beattie wrote:
On Apr 28, 10:25*am, Dave wrote:





Hi all,

I have an mtb with a SRAM X0 rear der and a SRAM twist shifter. *I was
previously running a 9-speed 11-34 SRAM cassette (has a red spider,
don't know the model) with a triple front 42-32-22.

To give myself more usable gears (I never used the granny with the
11-34), I switched the rear cassette to a SRAM PG970 road cassette,
12-26. *Still using the triple front. *Chain is well used but still
within normal range according to my tool.

Surprisingly, shift quality is noticeably poorer after changing the
cassette. *The chain doesn't hesitate, but there is a noticeable thunk
(more a feeling than a sound). *This is distracting when shifting
under load. *The derailleur is properly adjusted.

Anything I can do to remedy this? *Would a different cassette yield
better shifting? *Any other tips? *I like close spacing in back and
would prefer to keep my 3x9 setup.

Wide range derailleurs never feel as precise on narrow range
cassettes, generally because they are pushing around so much chain.
Assuming that your chain is still in good shape (never a given,
notwithstanding measurement tool -- try using a steel ruler instead to
see if the two agree), try shortening the chain. *Also make sure that
your cables are well adjusted and lubricated. A bent derailleur hanger
also makes more of a difference in the small, closely spaced gears,
IMO. -- Jay Beattie.- Hide quoted text -

- Show quoted text -

I forgot to mention -- after you shorten your chain, play around with
your "b" adjuster screw to see if increasing/decreasing chain wrap
makes a difference. -- Jay Beattie.

On Apr 28, 11:13*am, Jay Beattie wrote:
On Apr 28, 10:56*am, Jay Beattie wrote:



On Apr 28, 10:25*am, Dave wrote:

Hi all,

I have an mtb with a SRAM X0 rear der and a SRAM twist shifter. *I was
previously running a 9-speed 11-34 SRAM cassette (has a red spider,
don't know the model) with a triple front 42-32-22.

To give myself more usable gears (I never used the granny with the
11-34), I switched the rear cassette to a SRAM PG970 road cassette,
12-26. *Still using the triple front. *Chain is well used but still
within normal range according to my tool.

Surprisingly, shift quality is noticeably poorer after changing the
cassette. *The chain doesn't hesitate, but there is a noticeable thunk
(more a feeling than a sound). *This is distracting when shifting
under load. *The derailleur is properly adjusted.

Anything I can do to remedy this? *Would a different cassette yield
better shifting? *Any other tips? *I like close spacing in back and
would prefer to keep my 3x9 setup.

Wide range derailleurs never feel as precise on narrow range
cassettes, generally because they are pushing around so much chain.
Assuming that your chain is still in good shape (never a given,
notwithstanding measurement tool -- try using a steel ruler instead to
see if the two agree), try shortening the chain. *Also make sure that
your cables are well adjusted and lubricated. A bent derailleur hanger
also makes more of a difference in the small, closely spaced gears,
IMO. -- Jay Beattie.- Hide quoted text -

- Show quoted text -

I forgot to mention -- after you shorten your chain, play around with
your "b" adjuster screw to see if increasing/decreasing chain wrap
makes a difference. -- Jay Beattie.

Excellent suggestion...the b-screw is an adjustment I'd overlooked.
I'll try that.

"Dave" wrote in message
...
Hi all,

I have an mtb with a SRAM X0 rear der and a SRAM twist shifter. I was
previously running a 9-speed 11-34 SRAM cassette (has a red spider,
don't know the model) with a triple front 42-32-22.

To give myself more usable gears (I never used the granny with the
11-34), I switched the rear cassette to a SRAM PG970 road cassette,
12-26. Still using the triple front. Chain is well used but still
within normal range according to my tool.

Surprisingly, shift quality is noticeably poorer after changing the
cassette. The chain doesn't hesitate, but there is a noticeable thunk
(more a feeling than a sound). This is distracting when shifting
under load. The derailleur is properly adjusted.

Anything I can do to remedy this? Would a different cassette yield
better shifting? Any other tips? I like close spacing in back and
would prefer to keep my 3x9 setup.

Long-cage mountain bike derailleurs, and that's what you'd have if the
original cassette was an 11-34, don't like smaller cassettes. You can
try various adjustments, including shortening the chain and playing with
the b-tension screw (which generally needs to be all the way "out" so
you get as much chain wrap as possible), but the problem is caused by
the derailleur hanging too far below the cogs. A derailleur made for a
larger cassette has the upper jockey wheel placed lower, as it moves to
larger cogs, than one made for smaller cassettes. The further away the
jockey wheel is from the cassette, the less precise the shifting will
be.

In my perfect world, for bikes with replacable derailleur hangers,
they'd make them in a couple different lengths so you could optimize
your shifting.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

On Apr 28, 12:52*pm, "Mike Jacoubowsky"
wrote:
"Dave" wrote in message

...



Hi all,

I have an mtb with a SRAM X0 rear der and a SRAM twist shifter. *I was
previously running a 9-speed 11-34 SRAM cassette (has a red spider,
don't know the model) with a triple front 42-32-22.

To give myself more usable gears (I never used the granny with the
11-34), I switched the rear cassette to a SRAM PG970 road cassette,
12-26. *Still using the triple front. *Chain is well used but still
within normal range according to my tool.

Surprisingly, shift quality is noticeably poorer after changing the
cassette. *The chain doesn't hesitate, but there is a noticeable thunk
(more a feeling than a sound). *This is distracting when shifting
under load. *The derailleur is properly adjusted.

Anything I can do to remedy this? *Would a different cassette yield
better shifting? *Any other tips? *I like close spacing in back and
would prefer to keep my 3x9 setup.

Long-cage mountain bike derailleurs, and that's what you'd have if the
original cassette was an 11-34, don't like smaller cassettes. You can
try various adjustments, including shortening the chain and playing with
the b-tension screw (which generally needs to be all the way "out" so
you get as much chain wrap as possible), but the problem is caused by
the derailleur hanging too far below the cogs. A derailleur made for a
larger cassette has the upper jockey wheel placed lower, as it moves to
larger cogs, than one made for smaller cassettes. The further away the
jockey wheel is from the cassette, the less precise the shifting will
be.

In my perfect world, for bikes with replacable derailleur hangers,
they'd make them in a couple different lengths so you could optimize
your shifting.

--Mike Jacoubowsky
Chain Reaction Bicycleswww.ChainReaction.com
Redwood City & Los Altos, CA USA

Another problem is the angle the parallelogram linkage is set at --
wide range derailleurs are more steeply angled, so the jockey wheel
drops down more with each downshift. So a wide range derailleur that
might work well in the high gears on a narrow cassette will be too far
away in the low gears. Shimano Saint derailleur has a widget that
adjusts the angle of the path of the jockey wheel for wide or narrow
ranges.

-pm

In article
,
Dave wrote:

Hi all,

I have an mtb with a SRAM X0 rear der and a SRAM twist shifter. I was
previously running a 9-speed 11-34 SRAM cassette (has a red spider,
don't know the model) with a triple front 42-32-22.

To give myself more usable gears (I never used the granny with the
11-34), I switched the rear cassette to a SRAM PG970 road cassette,
12-26. Still using the triple front. Chain is well used but still
within normal range according to my tool.

Surprisingly, shift quality is noticeably poorer after changing the
cassette. The chain doesn't hesitate, but there is a noticeable thunk
(more a feeling than a sound). This is distracting when shifting
under load. The derailleur is properly adjusted.

Anything I can do to remedy this? Would a different cassette yield
better shifting? Any other tips? I like close spacing in back and
would prefer to keep my 3x9 setup.

Did you remove four links from the chain?
Better yet, fit the chain to big-big according to
the well known chain fitting method.

--
Michael Press

On Apr 28, 3:04*pm, Michael Press wrote:
In article
,



*Dave wrote:
Hi all,

I have an mtb with a SRAM X0 rear der and a SRAM twist shifter. *I was
previously running a 9-speed 11-34 SRAM cassette (has a red spider,
don't know the model) with a triple front 42-32-22.

To give myself more usable gears (I never used the granny with the
11-34), I switched the rear cassette to a SRAM PG970 road cassette,
12-26. *Still using the triple front. *Chain is well used but still
within normal range according to my tool.

Surprisingly, shift quality is noticeably poorer after changing the
cassette. *The chain doesn't hesitate, but there is a noticeable thunk
(more a feeling than a sound). *This is distracting when shifting
under load. *The derailleur is properly adjusted.

Anything I can do to remedy this? *Would a different cassette yield
better shifting? *Any other tips? *I like close spacing in back and
would prefer to keep my 3x9 setup.

Did you remove four links from the chain?
Better yet, fit the chain to big-big according to
the well known chain fitting method.

--
Michael Press

So after taking a look at it again I realize that chain wrap is indeed
the problem. There is a ton of space between the cogs and the jockey
wheel, and it doesn't vary much throughout the stroke. Backing the b-
tension screw out helped a bit, but I guess the derailleur is
positioned to support a big cassette. Don't dirt jumpers use road
cassettes? Wonder what they use.

Anyway, thanks for the suggestions.

In article 7c3b1a74-58ff-427d-9460-
,
says...


Hi all,

I have an mtb with a SRAM X0 rear der and a SRAM twist shifter. I
was
previously running a 9-speed 11-34 SRAM cassette (has a red
spider,
don't know the model) with a triple front 42-32-22.

To give myself more usable gears (I never used the granny with the
11-34), I switched the rear cassette to a SRAM PG970 road
cassette,
12-26. Still using the triple front. Chain is well used but still
within normal range according to my tool.

Surprisingly, shift quality is noticeably poorer after changing the
cassette. The chain doesn't hesitate, but there is a noticeable thunk
(more a feeling than a sound). This is distracting when shifting
under load. The derailleur is properly adjusted.

Anything I can do to remedy this? Would a different cassette yield
better shifting? Any other tips? I like close spacing in back and
would prefer to keep my 3x9 setup.
1. Adjust B screw, see if that helps.
2. Shorten chain, see if that helps.
3. Replace chain if 1. & 2. don't work.
4. Replacing the rear derailleur shouldn't be necesary, but the long
cage may not shift quite as zippy as a shorter cage with the tighter
cassette.

On Apr 28, 1:33*pm, pm wrote:
Shimano Saint derailleur has a widget that
adjusts the angle of the path of the jockey wheel for wide or narrow
ranges.

-pm

You mean like 1st-generation Campy Chorus had 20 years ago?