Question: Excessively loose chain tension when back-pedaling

[[email protected]]

Sorry my wording may not be precise, but my wife's bike (Lemond Arivee
with Ultegra Groupo) has excessively loose chain tension when pedaling
backwards. When I put the bike up on my stand and looked at it closely
I can see that the rear derailleur pulley moves toward bike when
backwards pedaling instead of keeping the tension constant.

The bike is a 2003 model with approx 500 miles on it and I haven't
changed/adjusted anything on it. Chain tension and shifting is fine
when pedaling forward -- any ideas on how I can fix it? One thought is
that my wife did put a new tube in the tire on her last ride and,
between us , might have adjusted something wrongly.

Anyway -- thanks for any advice.

Regards,

Tim

 

[spin156]

I agree 100% with Pete. Clean and lube the drivetrain first and
then
see if you still have the problem. I'll bet it goes away. Any
"gummy-ness" will cause the exact problem you are experiencing.

-- spin

 

[[email protected]]

Wow -- good point and that makes sense. I need to clean the chain! I'll
look into it tomorrow.

Cheers,

Tim

 

[(PeteCresswell)]

Per [email protected]:
>The bike is a 2003 model with approx 500 miles on it and I haven't
>changed/adjusted anything on it. Chain tension and shifting is fine
>when pedaling forward -- any ideas on how I can fix it? One thought is...

On mine, that happens when there's enough crud on the chain to make the links a
little stiff.

Try wiping the chain down, dripping some oil into it, then wiping it down again
and see if the problem goes away.
--
PeteCresswell

 

[(PeteCresswell)]

Per (PeteCresswell):
>On mine, that happens when there's enough crud on the chain to make the links a
>little stiff.

And I should add that if you der has to cover enough range and is in the
'sloppiest' gear (i.e. it has to take up the most slack) some movement is
probably normal.

Try to provoke the problem in the very highest gear, and then in the very lowest
gear (including front chain wheel shifts) - and see if the problem comes/goes
depending.
--
PeteCresswell

 

[Werehatrack]

On 18 Sep 2005 14:39:09 -0700, [email protected] wrote:

>Sorry my wording may not be precise, but my wife's bike (Lemond Arivee
>with Ultegra Groupo) has excessively loose chain tension when pedaling
>backwards.

Derailleur systems are not intended to be pedalled backwards.

>When I put the bike up on my stand and looked at it closely
>I can see that the rear derailleur pulley moves toward bike when
>backwards pedaling instead of keeping the tension constant.

Yes. This is normal.

>The bike is a 2003 model with approx 500 miles on it and I haven't
>changed/adjusted anything on it. Chain tension and shifting is fine
>when pedaling forward -- any ideas on how I can fix it? One thought is
>that my wife did put a new tube in the tire on her last ride and,
>between us , might have adjusted something wrongly.
>
>Anyway -- thanks for any advice.

The only relevant advice is "Don't pedal backwards." The system is
not designed to keep the chain on the correct rear or front procket
when you back-pedal; doing so may cause the chain to apply excessive
side-force to the ders when the chain jumps to the wrong sprockets and
tracks back against the der. It may also cause the chain to jump
completely off the front sprockets, with potentially hazardous or
damaging consequences.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.