New Road bike - having issues with the front Derailleur



E

ESS

Guest
I have a new road bike with Shimano Tiagra front and rear Derailleurs.
When I am in the lowest cog in the rear and the lowest cog in the front
the chain rubs the front Derailleur. The manual says you can use the
left shifter to move the Derailleur just a bit to ease the noise but not
shift into the top cog in the front. When I do this it seems to move the
front Derailleur too much. Any thoughts on why this might be? Can I
adjust the indexed shift? Any help would be appreciated.

Ethan

-------------
Get FREE newsgroup access from http://www.cheap56k.com
 
ESS wrote:
> I have a new road bike with Shimano Tiagra front and rear Derailleurs.
> When I am in the lowest cog in the rear and the lowest cog in the front
> the chain rubs the front Derailleur. The manual says you can use the
> left shifter to move the Derailleur just a bit to ease the noise but not
> shift into the top cog in the front. When I do this it seems to move the
> front Derailleur too much. Any thoughts on why this might be? Can I
> adjust the indexed shift? Any help would be appreciated.
>
> Ethan
>
> -------------
> Get FREE newsgroup access from http://www.cheap56k.com


I am assuming that your are in the smallest cog both in the front and
rear. If that is the case, you should avoid this combination.

Andres
 
S

Sorni

Guest
ESS wrote:
> I have a new road bike with Shimano Tiagra front and rear Derailleurs.
> When I am in the lowest cog in the rear and the lowest cog in the
> front the chain rubs the front Derailleur. The manual says you can
> use the left shifter to move the Derailleur just a bit to ease the
> noise but not shift into the top cog in the front. When I do this it
> seems to move the front Derailleur too much. Any thoughts on why this
> might be? Can I adjust the indexed shift? Any help would be
> appreciated.


You are "cross-chained" -- small ring in front, smallest cog in back. Even
if the trim took away the noise (no sure thing), you should avoid that
combination as it stresses the drivetrain more than necessary.

Shift to the middle (ish) of the cassette (in back) and to the bigger ring
in front. Your cadence should remain roughly the same, and then you can
adjust things from there...

Happy riding!

BS (no, really)
 
P

Peter Cole

Guest
ESS wrote:
> I have a new road bike with Shimano Tiagra front and rear Derailleurs.
> When I am in the lowest cog in the rear and the lowest cog in the front
> the chain rubs the front Derailleur. The manual says you can use the
> left shifter to move the Derailleur just a bit to ease the noise but not
> shift into the top cog in the front. When I do this it seems to move the
> front Derailleur too much. Any thoughts on why this might be? Can I
> adjust the indexed shift? Any help would be appreciated.


Sounds like you need to make a very small adjustment to your front
derailer. It may be that the derailer stop limit screw or the cable
adjuster need a small change. Try looking at Sheldon Brown's and/or the
Park Tool site for adjustment how-to's.
 
B

Barnard Frederick

Guest
ESS says...

> I have a new road bike with Shimano Tiagra front and rear Derailleurs.
> When I am in the lowest cog in the rear and the lowest cog in the front
> the chain rubs the front Derailleur. The manual says you can use the
> left shifter to move the Derailleur just a bit to ease the noise but not
> shift into the top cog in the front. When I do this it seems to move the
> front Derailleur too much. Any thoughts on why this might be? Can I
> adjust the indexed shift? Any help would be appreciated.
>
> Ethan


Not only is it rubbing your front derailleur the wrong way, it is also
very hard on your drivetrain. Don't use that combination, or the big
ring, big sprocket combination. Ever. With a 9 speed system, I try not
to use any but six gears for any chainring. The smallest six go with
the big ring, and the largest six go with the smallest ring. You may be
able to use all nine with the middle ring, but you may hear a little
extra chain chatter even then. Assuming that everything is pretty well
adjusted, a good way to tell when you are trying to use rear gears
outside of the comfort zone of the chainring you are on is when the
noise level from the chain goes up.
 
B

Booker C. Bense

Guest
-----BEGIN PGP SIGNED MESSAGE-----

In article <[email protected]>,
Barnard Frederick <[email protected]> wrote:
>ESS says...
>
>> I have a new road bike with Shimano Tiagra front and rear Derailleurs.
>> When I am in the lowest cog in the rear and the lowest cog in the front
>> the chain rubs the front Derailleur. The manual says you can use the
>> left shifter to move the Derailleur just a bit to ease the noise but not
>> shift into the top cog in the front. When I do this it seems to move the
>> front Derailleur too much. Any thoughts on why this might be? Can I
>> adjust the indexed shift? Any help would be appreciated.
>>
>> Ethan

>
>Not only is it rubbing your front derailleur the wrong way, it is also
>very hard on your drivetrain. Don't use that combination, or the big
>ring, big sprocket combination. Ever. With a 9 speed system, I try not
>to use any but six gears for any chainring. The smallest six go with
>the big ring, and the largest six go with the smallest ring. You may be
>able to use all nine with the middle ring, but you may hear a little
>extra chain chatter even then. Assuming that everything is pretty well
>adjusted, a good way to tell when you are trying to use rear gears
>outside of the comfort zone of the chainring you are on is when the
>noise level from the chain goes up.


It's a bike, use it. The cross-chaining stuff is another often
repeated bike shop myth with no real evidence that it causes
any real damage to the bike. I cross-chain whenever I find it
convient and my stuff doesn't wear out any faster than anybody
elses.

The only research I've seen says that chain angle doesn't matter
at all across the range of a typical 9 speed cluster. However,
this research also says that for a given ratio if you can get
that ratio in bigger gears, vs using smaller gears then it's more
efficient.

Since there are slightly better gears available on a triple that
don't cause noise you might as well use them. With modern bikes
with short chainstays and indexed shifting, you can't really use
all the gears anyway as the derailers don't have enough leeway
for the larger angles that a short chainstay requires. So the
"damage" crosschaining does to your gears in mostly the rubbing
on the derailer and that fundementally can't be fixed since you
can't lengthen the chainstays or widen the derailer cage.

While your bike may have 24, 27 or 30 gears, there are many
duplicates or gears so close in ratio that you can't
differentiate them. At best you likely have 14 or 15 distinct
gears.

_ Booker C. Bense


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C

catzz66

Guest
Booker C. Bense wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
>
> In article <[email protected]>,
> Barnard Frederick <[email protected]> wrote:
>
>>ESS says...
>>
>>
>>>I have a new road bike with Shimano Tiagra front and rear Derailleurs.
>>>When I am in the lowest cog in the rear and the lowest cog in the front
>>>the chain rubs the front Derailleur. The manual says you can use the
>>>left shifter to move the Derailleur just a bit to ease the noise but not
>>>shift into the top cog in the front. When I do this it seems to move the
>>>front Derailleur too much. Any thoughts on why this might be? Can I
>>>adjust the indexed shift? Any help would be appreciated.
>>>
>>>Ethan

>>
>>Not only is it rubbing your front derailleur the wrong way, it is also
>>very hard on your drivetrain. Don't use that combination, or the big
>>ring, big sprocket combination. Ever. With a 9 speed system, I try not
>>to use any but six gears for any chainring. The smallest six go with
>>the big ring, and the largest six go with the smallest ring. You may be
>>able to use all nine with the middle ring, but you may hear a little
>>extra chain chatter even then. Assuming that everything is pretty well
>>adjusted, a good way to tell when you are trying to use rear gears
>>outside of the comfort zone of the chainring you are on is when the
>>noise level from the chain goes up.

>
>
> It's a bike, use it. The cross-chaining stuff is another often
> repeated bike shop myth with no real evidence that it causes
> any real damage to the bike. I cross-chain whenever I find it
> convient and my stuff doesn't wear out any faster than anybody
> elses.
>
> The only research I've seen says that chain angle doesn't matter
> at all across the range of a typical 9 speed cluster. However,
> this research also says that for a given ratio if you can get
> that ratio in bigger gears, vs using smaller gears then it's more
> efficient.
>
> Since there are slightly better gears available on a triple that
> don't cause noise you might as well use them. With modern bikes
> with short chainstays and indexed shifting, you can't really use
> all the gears anyway as the derailers don't have enough leeway
> for the larger angles that a short chainstay requires. So the
> "damage" crosschaining does to your gears in mostly the rubbing
> on the derailer and that fundementally can't be fixed since you
> can't lengthen the chainstays or widen the derailer cage.
>
> While your bike may have 24, 27 or 30 gears, there are many
> duplicates or gears so close in ratio that you can't
> differentiate them. At best you likely have 14 or 15 distinct
> gears.
>
> _ Booker C. Bense
>


When you hear gear/chain noise, that ought to be your clue to go to
another chain ring. Most casual riders would take a long time to wear
out a chain but it is not a bad idea to use good technique anyhow.
 
L

Llatikcuf

Guest
Barnard Frederick wrote:
>
> Not only is it rubbing your front derailleur the wrong way, it is also
> very hard on your drivetrain. Don't use that combination, or the big
> ring, big sprocket combination. Ever. With a 9 speed system, I try not
> to use any but six gears for any chainring.


Why so limited? I agree with the big and small ring, but why the
middle?

In the 30, I use all but the 12 and 13.
In the 42, I use the entire range, It's centered, why not?
In the 52, I use the bottom 6.

No problems with premature wear.

-nate
 
On Tue, 2 May 2006 21:25:24 +0000 (UTC), Booker C. Bense
<[email protected]>
wrote:

>It's a bike, use it. The cross-chaining stuff is another often
>repeated bike shop myth with no real evidence that it causes
>any real damage to the bike. I cross-chain whenever I find it
>convient and my stuff doesn't wear out any faster than anybody
>elses.
>
>The only research I've seen says that chain angle doesn't matter
>at all across the range of a typical 9 speed cluster. However,
>this research also says that for a given ratio if you can get
>that ratio in bigger gears, vs using smaller gears then it's more
>efficient.


[snip]

>_ Booker C. Bense


Dear Booker,

Possibly this is the research that you have in mind,
Professor Spicer's chain efficiency tests at Johns Hopkins?

http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf

At the same power, chain efficiency improves slightly when
we make the smallest gear as large as possible (52x16
instead of 52x11) and keep the chain tension and speed high
(52x11 instead of 52x16).

Drat! The advantage of a larger rear cog's size is pretty
much canceled out by its lower tension.

Neither chain offset (cross-chaining) nor lubrication (even
running dry) made as much difference as the those two
factors.

Cheers,

Carl Fogel
 
D

David L. Johnson

Guest
On Tue, 02 May 2006 13:14:38 -0400, ESS wrote:

> I have a new road bike with Shimano Tiagra front and rear Derailleurs.
> When I am in the lowest cog in the rear and the lowest cog in the front
> the chain rubs the front Derailleur.


"Doctor, it hurts when I do this." "Don't do that."

This advice may seem like that old joke, but there is no reason to use
that gear combination. Figure out the gear ratios (front/back --- number
of teeth), and you'll see that the small-small combination is the same
as the big, third-from biggest (or thereabouts, depending on your setup).
Use that other combination instead. Using a "long reach" gear,
small-smal or big-big, is a bad idea, in that the chain and cogs will
wear excessively.

il The manual says you can use the
> left shifter to move the Derailleur just a bit to ease the noise but not
> shift into the top cog in the front. When I do this it seems to move the
> front Derailleur too much. Any thoughts on why this might be?


Typically with this it will be imposible to avoid some noise. Either the
chain will rub on the derailleur, or it will rub on the big chainring.


--

David L. Johnson

__o | I believe that the motion picture is destined to revolutionize
_`\(,_ | our educational system and that in a few years it will supplant
(_)/ (_) | largely, if not entirely, the use of textbooks -- Thomas
Edison, 1922
 
Q

Qui si parla Campagnolo

Guest
ESS wrote:
> I have a new road bike with Shimano Tiagra front and rear Derailleurs.
> When I am in the lowest cog in the rear and the lowest cog in the front
> the chain rubs the front Derailleur. The manual says you can use the
> left shifter to move the Derailleur just a bit to ease the noise but not
> shift into the top cog in the front. When I do this it seems to move the
> front Derailleur too much. Any thoughts on why this might be? Can I
> adjust the indexed shift? Any help would be appreciated.
>
> Ethan


If it's 'NEW", take it back to where you got it and have a real wrench,
not an assembler, adjust the FD.
 
Q

Qui si parla Campagnolo

Guest
[email protected] wrote:
> ESS wrote:
> > I have a new road bike with Shimano Tiagra front and rear Derailleurs.
> > When I am in the lowest cog in the rear and the lowest cog in the front
> > the chain rubs the front Derailleur. The manual says you can use the
> > left shifter to move the Derailleur just a bit to ease the noise but not
> > shift into the top cog in the front. When I do this it seems to move the
> > front Derailleur too much. Any thoughts on why this might be? Can I
> > adjust the indexed shift? Any help would be appreciated.
> >
> > Ethan
> >
> > -------------
> > Get FREE newsgroup access from http://www.cheap56k.com

>
> I am assuming that your are in the smallest cog both in the front and
> rear. If that is the case, you should avoid this combination.
>
> Andres


Lowest or smallest? Yikes, I'm sounding like Sheldon now. If in
smallest and smallest, it will rub, don go there.
 
P

Pat Lamb

Guest
Peter Cole wrote:
> ESS wrote:
>> I have a new road bike with Shimano Tiagra front and rear Derailleurs.
>> When I am in the lowest cog in the rear and the lowest cog in the
>> front the chain rubs the front Derailleur. The manual says you can use
>> the left shifter to move the Derailleur just a bit to ease the noise
>> but not shift into the top cog in the front. When I do this it seems
>> to move the front Derailleur too much. Any thoughts on why this might
>> be? Can I adjust the indexed shift? Any help would be appreciated.

>
> Sounds like you need to make a very small adjustment to your front
> derailer. It may be that the derailer stop limit screw or the cable
> adjuster need a small change. Try looking at Sheldon Brown's and/or the
> Park Tool site for adjustment how-to's.


That's the way I read it, too ("lowest cog" meaning low gear, meaning
biggest diameter cog in back, smallest chainwheel in front). The Tiagra
lets you trim the front derailer (OP's move it to ease the noise), but
only in the middle chainwheel.

Look for the screw marked "L" on the front derailer and back it out a
quarter turn.

Pat
 

>
> That's the way I read it, too ("lowest cog" meaning low gear, meaning
> biggest diameter cog in back, smallest chainwheel in front). The Tiagra
> lets you trim the front derailer (OP's move it to ease the noise), but
> only in the middle chainwheel.


Minor point: the Tiagra front shifter lets you trim in the smallest
chainring. Nonetheless, all of the other advice given in this thread
is more important.

Leland