Compact crank - chainline problem?

PatC said:

Hi. Amateur mechanic here. I recently installed a FSA carbon compact
frame on my Colnago Asso Campy Centaur 10 speed. I installed a FSA ISIS
108mm bottom bracket.

Here are my symptoms:

Symptom 1: If I shift to the small chainring and the smallest cog, the
chain drags against the large ring. I know I should never be in this gear,
but I don't think it should be dragging.

This isn't uncommon, especially on bikes with short chainstays. It's
true, you should _never_ ride in this gear--it's worse with "compact"
cranks.

I doubt there's anything wrong with your chainline, but it wouldn't hurt
to grab a ruler and measure it. Should normally be 43.5 mm for a
typical double, though I prefer something a bit closer in for a
"compact" setup, 'cause I like to be able to use the large/large
combination.

Quoted message said:

Symptom 2: If I'm in the large ring and shift into the small cog, it takes
a while for the chain to drop in.

If you're speaking of the small cog in back, it's likely cable friction,
or possibly a bent derailer hanger. See:

http://sheldonbrown.com/derailer-adjustment

Quoted message said:

Third thing, and unrelated, it doesn't seem like the standard Centaur
(braze on) front derailleur drops low enough for the compact crank.

Should

Quoted message said:

I upgrade to the Campy compact front derailleur to improve the

situation?

Quoted message said:

What's that thing all about?

If you're speaking of shifting down to the small ring in front, this is
very likely the cause of your problem. Front derailer performance
deteriorates rapidly if the cage is too high above the chainrings.

I've said it before, I'll say it again: Front derailer braze-ons are the
work of SATAN!

Quoted message said:

I've adjusted the derailleur mercilessly
with no improvement, and I've cleaned the cable and lubed it. Some one
suggested I go ahead and change the cables, which probably isn't a bad idea
anyways.

So, do I have a chainline problem? It seems if the crank were a millimeter
further out, it wouldn't do this. If so, is there such a thing as a ISIS
shim? Or, do I have the right size BB?

I think your BB is correct. It is possible to install a spacer washer
under the right side BB retaining ring to move everything to the right a
skosh. Probably not indicated in your case though.

Sheldon "Retro Me, Satanas!" Brown
+-----------------------------------------+
| He not busy being born is busy dying. |
| -Bob Dylan |
+-----------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

PatC said:

Hi. Amateur mechanic here. I recently installed a FSA carbon compact
frame on my Colnago Asso Campy Centaur 10 speed. I installed a FSA ISIS
108mm bottom bracket.

Here are my symptoms:

Symptom 1: If I shift to the small chainring and the smallest cog, the
chain drags against the large ring. I know I should never be in this gear,
but I don't think it should be dragging.

It will drag not only due to 10s...lots of cogs way out from the center
of the bicycle, but also 16t difference and also lots of pickup pins and
ramps on the big ring-NORMAL.

Quoted message said:

Symptom 2: If I'm in the large ring and shift into the small cog, it takes
a while for the chain to drop in. I've adjusted the derailleur mercilessly
with no improvement, and I've cleaned the cable and lubed it. Some one
suggested I go ahead and change the cables, which probably isn't a bad idea
anyways.

Make sure the front lip of the front der outside cage is angled or bent
a wee bit toward the rings.

Quoted message said:

So, do I have a chainline problem? It seems if the crank were a millimeter
further out, it wouldn't do this. If so, is there such a thing as a ISIS
shim? Or, do I have the right size BB?

You have the right BB, no shims needed. Just don't shift there. Ya know,
if you have a 5 speed in your car, it will buck and stumble if you start
from a stop sign in 4th gear...no problem, just some 'technique'.

Quoted message said:

Is Symptom 2 related? Does it call for a new shifter cable? If so, any
suggestions for a cable brand? I've seen Nokon, Campy, Delta Aztec and
Avid, all at different price points. Any opinions?

Third thing, and unrelated, it doesn't seem like the standard Centaur
(braze on) front derailleur drops low enough for the compact crank. Should
I upgrade to the Campy compact front derailleur to improve the situation?
What's that thing all about?

The compact front der has longer arms and a wider back cage but the
brazeon on the frame is the problem. File the notch lower-reinstall.

PatC said:

Symptom 1: If I shift to the small chainring and the smallest cog, the
chain drags against the large ring. I know I should never be in this gear,
but I don't think it should be dragging.

It always has for me, even back in the 5-gear freewheel days. No big
deal.

Quoted message said:

Symptom 2: If I'm in the large ring and shift into the small cog, it
takes a while for the chain to drop in.

Adjustment problem? There are two. You can adjust the the tension, which
affects all gears, or just adjust the limit screw, which will (assuming
that the cable is not too tight) give you a bit more for that last gear.

Quoted message said:

Should I upgrade to the Campy compact front derailleur to improve the
situation? What's that thing all about?

It's all about selling derailleurs. I have an "uber"-compact crank, 46/30
(mountain bike crank) and an old Campy front derailleur and it works fine.
But your symptoms are not related to the front derailleur, anyway.

--

David L. Johnson

__o | Deserves death! I daresay he does. Many that live deserve
_`\(,_ | death. And some that die deserve life. Can you give it to
(_)/ (_) | them? Then do not be too eager to deal out death in judgement.
-- J. R. R. Tolkein

Qui Si Parla Campagnolo <[email hidden]> wrote in
news:1110748895.edb4ad7bfab0c4a2720f1284bf6a4587@teranews:

Quoted message said:

PatC said:

Hi. Amateur mechanic here. I recently installed a FSA carbon
compact frame on my Colnago Asso Campy Centaur 10 speed. I installed
a FSA ISIS 108mm bottom bracket.

Here are my symptoms:

Symptom 1: If I shift to the small chainring and the smallest cog,
the chain drags against the large ring. I know I should never be in
this gear, but I don't think it should be dragging.

You have the right BB, no shims needed. Just don't shift there. Ya
know, if you have a 5 speed in your car, it will buck and stumble if
you start from a stop sign in 4th gear...no problem, just some
'technique'.

Quoted message said:

Is Symptom 2 related? Does it call for a new shifter cable? If so,
any suggestions for a cable brand? I've seen Nokon, Campy, Delta
Aztec and Avid, all at different price points. Any opinions?

Third thing, and unrelated, it doesn't seem like the standard Centaur
(braze on) front derailleur drops low enough for the compact crank.
Should I upgrade to the Campy compact front derailleur to improve
the situation? What's that thing all about?

The compact front der has longer arms and a wider back cage but the
brazeon on the frame is the problem. File the notch lower-reinstall.

Do you mean to file the actual slot that allows the derailleur to move up
and down, to make the slot longer?

I don't believe my rear derailleur hanger is bent. I may try a new cable
and see how that goes. I'll probably have to rewrap my bars (just redid
them )-: I'm also heading out to read Brown's instructions. That's
usually interesting!

Thanks everyone for the responses. I thought I might get the "don't use
that gear" response, but wanted to make sure.

Pat c-

Quoted message said:

Do you mean to file the actual slot that allows the derailleur to move up
and down, to make the slot longer?

I don't believe my rear derailleur hanger is bent. I may try a new cable
and see how that goes. I'll probably have to rewrap my bars (just redid
them )-: I'm also heading out to read Brown's instructions. That's
usually interesting!

Thanks everyone for the responses. I thought I might get the "don't use
that gear" response, but wanted to make sure.

Yes, file the bottom of the slot lower to allow for lower placement of
the front der. very common problem and solution.

PatC said:

Hi. Amateur mechanic here. I recently installed a FSA carbon compact
frame on my Colnago Asso Campy Centaur 10 speed. I installed a FSA ISIS
108mm bottom bracket.

Here are my symptoms:

Symptom 1: If I shift to the small chainring and the smallest cog, the
chain drags against the large ring. I know I should never be in this gear,
but I don't think it should be dragging.

Symptom 2: If I'm in the large ring and shift into the small cog, it takes
a while for the chain to drop in. I've adjusted the derailleur mercilessly
with no improvement, and I've cleaned the cable and lubed it. Some one
suggested I go ahead and change the cables, which probably isn't a bad idea
anyways.

So, do I have a chainline problem? It seems if the crank were a millimeter
further out, it wouldn't do this. If so, is there such a thing as a ISIS
shim? Or, do I have the right size BB?

Is Symptom 2 related? Does it call for a new shifter cable? If so, any
suggestions for a cable brand? I've seen Nokon, Campy, Delta Aztec and
Avid, all at different price points. Any opinions?

Third thing, and unrelated, it doesn't seem like the standard Centaur
(braze on) front derailleur drops low enough for the compact crank. Should
I upgrade to the Campy compact front derailleur to improve the situation?
What's that thing all about?

I have been reading this and other "compact crank" threads with interest
and I am considering going "compact" myself. However, I am concerned
about the chainline problems/chaindropping problems and other mechanical
issues which have been raised. Does anyone have views as to which
brand/type of compact crank/bottom bracket is likely to work best?

To the extent relevant,my current bike is a Calfee Luna Pro with Dura
Ace 9 (both of which are vintage 1998 or so). At the same time that I
convert to compact I will probably also move over to 10 speed, either
Dura Ace or Record, so I am flexible in terms of compatibilty with my
existing equipment.

I have seen in the various threads discussion of FSA carbon compact, FSA
megaExo and the Record compact (with side discussions as to whether the
"matching" record fdr is a worthwhile investment). Cost is not a
decisive factor for me (although no reason to waste money either...) and
lighter is better unless there are countervailing factors (durability,
strength, stiffness, etc.)

Any informed opinions would be welcome.

I am running three different brands of compact cranks on three
different bikes. Brands include Ritchey, Stronglight, and Sugino. I
run 48/34 and 50/34 up front and 12/30 or 11/32 in the rear. Not
racey, but it works for me. Shifting is totally reliable on all three
bikes. On my Rivendell Rambouillet with the Ritchey 50/34 up front and
the 11/32 in the rear, I get just a bit of rub on the large ring when
on the small ring in front and the small cog in the rear. I was going
to fool around with a spacer behind the cassette to move it out a hair,
and then I decided why bother. Just don't ride cross chained. I
wonder if chain line problems can be affected by the dish of the
wheel???

oops, what I meant was to put a spacer under the drive side bb cup to
move it out a hair and lessen the chain angle.

Joshua Mermelstein said:

PatC said:

Hi. Amateur mechanic here. I recently installed a FSA carbon compact
frame on my Colnago Asso Campy Centaur 10 speed. I installed a FSA
ISIS 108mm bottom bracket.

Here are my symptoms:
Symptom 1: If I shift to the small chainring and the smallest cog,
the chain drags against the large ring. I know I should never be in
this gear, but I don't think it should be dragging.

Symptom 2: If I'm in the large ring and shift into the small cog, it
takes a while for the chain to drop in. I've adjusted the derailleur
mercilessly with no improvement, and I've cleaned the cable and lubed
it. Some one suggested I go ahead and change the cables, which
probably isn't a bad idea anyways.

So, do I have a chainline problem? It seems if the crank were a
millimeter further out, it wouldn't do this. If so, is there such a
thing as a ISIS shim? Or, do I have the right size BB?
Is Symptom 2 related? Does it call for a new shifter cable? If so,
any suggestions for a cable brand? I've seen Nokon, Campy, Delta
Aztec and Avid, all at different price points. Any opinions?

Third thing, and unrelated, it doesn't seem like the standard Centaur
(braze on) front derailleur drops low enough for the compact crank.
Should I upgrade to the Campy compact front derailleur to improve the
situation? What's that thing all about?

I have been reading this and other "compact crank" threads with interest
and I am considering going "compact" myself. However, I am concerned
about the chainline problems/chaindropping problems and other mechanical
issues which have been raised. Does anyone have views as to which
brand/type of compact crank/bottom bracket is likely to work best?

To the extent relevant,my current bike is a Calfee Luna Pro with Dura
Ace 9 (both of which are vintage 1998 or so). At the same time that I
convert to compact I will probably also move over to 10 speed, either
Dura Ace or Record, so I am flexible in terms of compatibilty with my
existing equipment.

I have seen in the various threads discussion of FSA carbon compact, FSA
megaExo and the Record compact (with side discussions as to whether the
"matching" record fdr is a worthwhile investment). Cost is not a
decisive factor for me (although no reason to waste money either...) and
lighter is better unless there are countervailing factors (durability,
strength, stiffness, etc.)

Any informed opinions would be welcome.

Get the Gossomer MegaXO with external bearings if you want aluminum,
$179, the carbon version is $379...

Get a Campagnolo compact front der-works great...

Qui Si Parla Campagnolo said:

Joshua Mermelstein said:

PatC said:

Hi. Amateur mechanic here. I recently installed a FSA carbon
compact frame on my Colnago Asso Campy Centaur 10 speed. I installed
a FSA ISIS 108mm bottom bracket.

Here are my symptoms: Symptom 1: If I shift to the small chainring
and the smallest cog, the chain drags against the large ring. I know
I should never be in this gear, but I don't think it should be dragging.

Symptom 2: If I'm in the large ring and shift into the small cog, it
takes a while for the chain to drop in. I've adjusted the derailleur
mercilessly with no improvement, and I've cleaned the cable and lubed
it. Some one suggested I go ahead and change the cables, which
probably isn't a bad idea anyways.

So, do I have a chainline problem? It seems if the crank were a
millimeter further out, it wouldn't do this. If so, is there such a
thing as a ISIS shim? Or, do I have the right size BB?
Is Symptom 2 related? Does it call for a new shifter cable? If so,
any suggestions for a cable brand? I've seen Nokon, Campy, Delta
Aztec and Avid, all at different price points. Any opinions?

Third thing, and unrelated, it doesn't seem like the standard Centaur
(braze on) front derailleur drops low enough for the compact crank.
Should I upgrade to the Campy compact front derailleur to improve
the situation? What's that thing all about?

I have been reading this and other "compact crank" threads with
interest and I am considering going "compact" myself. However, I am
concerned about the chainline problems/chaindropping problems and
other mechanical issues which have been raised. Does anyone have views
as to which brand/type of compact crank/bottom bracket is likely to
work best?

To the extent relevant,my current bike is a Calfee Luna Pro with Dura
Ace 9 (both of which are vintage 1998 or so). At the same time that I
convert to compact I will probably also move over to 10 speed, either
Dura Ace or Record, so I am flexible in terms of compatibilty with my
existing equipment.

I have seen in the various threads discussion of FSA carbon compact,
FSA megaExo and the Record compact (with side discussions as to
whether the "matching" record fdr is a worthwhile investment). Cost is
not a decisive factor for me (although no reason to waste money
either...) and lighter is better unless there are countervailing
factors (durability, strength, stiffness, etc.)

Any informed opinions would be welcome.

Get the Gossomer MegaXO with external bearings if you want aluminum,
$179, the carbon version is $379...

Get a Campagnolo compact front der-works great...

Thanks Peter. I assume you are saying that with the campy compact I
should have better results than with a regular Campy (or Shimano) fd?
BTW, is there a problem with the Campy Compact or is it just not worth
the money?

In article <[email hidden]>,

PatC said:

Quoted message said:

Quoted message said:

Symptom 1: If I shift to the small chainring and the smallest cog,
the chain drags against the large ring. I know I should never be in
this gear, but I don't think it should be dragging.

You can shim the big ring out a little (as in a couple of Wheels
Manufacturing .4mm spacers) to avoid this. I did.

Quoted message said:

Quoted message said:

You have the right BB, no shims needed. Just don't shift there. Ya
know, if you have a 5 speed in your car, it will buck and stumble if
you start from a stop sign in 4th gear...no problem, just some
'technique'.

When you mix the wide spacing between rings with rub that precludes
using the two smallest cogs you can end up with very little overlap between
rings and a lot of ring changes on mild up-hill stretches.

Shimming the big ring avoided that for me and made little difference in
the small to big upshift quality.
--
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In 1913 the inflation adjusted (in 2003 dollars) exemption for single people
was $54,567, married couples' exemption $72,756, the next $363,783 was taxed
at 1%, and earnings over $9,094,578 were taxed at the top rate of 7%.