Front derailleur rigidity

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

Quoted message said:

The problem : Bad shifting from middle to little front ring under
load. I checked this at home: applied rear brake, shifted from middle
to little, pressed the pedal and saw as the chain bent the frame of
the derailleur about 2 mm outward. When I press the outer plate from
inside outward with my finger at the place wher the chain should be,
the whole frame first bends and only after that starts to rotate.
Front derailleur Deore 2003, installed 2 mm above big ring as manual
suggests. In my opinion the frame should not bend at all before it
starts to rotate under load. Am I right? The question is - are more
expensive models more rigid? Is there any table with exact figures of
rigidity of various front derailleurs? Maybe some tests performed by
some bicycle magazine? I would prefer heavier but more rigid.

I had the same problem. The problem was solved when I replaced the top swing
model (XT) with a downswing model (XT).

Lou

(Vladimir) said:

The problem : Bad shifting from middle to little front ring under
load. I checked this at home: applied rear brake, shifted from middle
to little, pressed the pedal and saw as the chain bent the frame of
the derailleur about 2 mm outward. When I press the outer plate from
inside outward with my finger at the place wher the chain should be,
the whole frame first bends and only after that starts to rotate.
Front derailleur Deore 2003, installed 2 mm above big ring as manual
suggests. In my opinion the frame should not bend at all before it
starts to rotate under load. Am I right? The question is - are more
expensive models more rigid? Is there any table with exact figures of
rigidity of various front derailleurs? Maybe some tests performed by
some bicycle magazine? I would prefer heavier but more rigid.

Or how about not shifting under load?

Or am I just being old-fashioned and don't know how bikes work nowadays?

I'm not _really_ trying to be a smart ass.

Ron

Ronsonic said:

On 5 Oct 2004 00:21:09 -0700, [email hidden] (Vladimir)

Quoted message said:

The problem : Bad shifting from middle to little front ring under
load. I checked this at home: applied rear brake, shifted from middle
to little, pressed the pedal and saw as the chain bent the frame of
the derailleur about 2 mm outward. When I press the outer plate from
inside outward with my finger at the place wher the chain should be,
the whole frame first bends and only after that starts to rotate.
Front derailleur Deore 2003, installed 2 mm above big ring as manual
suggests. In my opinion the frame should not bend at all before it
starts to rotate under load. Am I right? The question is - are more
expensive models more rigid? Is there any table with exact figures
of rigidity of various front derailleurs? Maybe some tests performed
by some bicycle magazine? I would prefer heavier but more rigid.

Or how about not shifting under load?

Or am I just being old-fashioned and don't know how bikes work
nowadays?

No... this is a technique that all should learn. Shifting to a larger
chainring is less of an issue because one can use finger pressure to force
the shift.

Deores will wear out rapidly, however. My 1-season Deore has sloppy pivots,
and I rarely shift... the whole thing rattles like crazy as I ride. Well,
as I ride on my road bike... I had to put it on my road bike because I
didn't have a 31.8 FD, so I used an inner tube as a shim to fit the
34.whatever-mm clamp.

--
Phil, Squid-in-Training

Ronsonic <> wrote in message news:<[email hidden]>...

Quoted message said:

Or how about not shifting under load?

Yes, I know, one should not shift under load. To be exact there is
some rate of load, when no one can succesfully shift. The question is
- is this rate of load the same for any front derailleur? And the
second - should the derailleur's frame bend under load before its
spring yelds to this load?

Quoted message said:

I'm not _really_ trying to be a smart ass.

What did you say? I am not native english speaking, you know :-)

"Phil, Squid-in-Training" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Deores will wear out rapidly, however. My 1-season Deore has sloppy pivots,
and I rarely shift...

How does a deraileur pivot wear with no (or little) shifting?

(Vladimir) said:

Ronsonic <> wrote in message news:<[email hidden]>...

Quoted message said:

Or how about not shifting under load?

Yes, I know, one should not shift under load. To be exact there is
some rate of load, when no one can succesfully shift. The question is
- is this rate of load the same for any front derailleur? And the
second - should the derailleur's frame bend under load before its
spring yelds to this load?

I don't have wide experience with a lot of different deraillers. Obviously some
will be better than others. All of them flex some, it would be heavy and
impractical to build them so rigid they wouldn't flex and then replace the
portion of the flex that's beneficial with springs and pivots. Something has to
give a little in that system. Unless it's shifting poorly I wouldn't worry about
it. They all shift poorly under load as far as I'm aware.

Quoted message said:

Quoted message said:

I'm not _really_ trying to be a smart ass.

What did you say? I am not native english speaking, you know :-)

Your English is very good, slang is difficult. A smart ass is someone trying to
be verbally abrasive in a clever way (usually not appreciated). Along the lines
of impudent or impertinent, but a more derisive word.

I'm an old guy who hasn't been keeping up with modern cycling technology and I
tend to rant about technological solutions to problems that either don't exist
or real problems that are easily solved by learning technique. So by saying I
wasn't _really_ trying to be a smart ass, I was deliberately being a little bit
of a smart ass. 😉

Ron

Richard Chan said:

"Phil, Squid-in-Training" <[email hidden]>
wrote in message
news:<[email hidden]>...

Quoted message said:

Deores will wear out rapidly, however. My 1-season Deore has sloppy
pivots, and I rarely shift...

How does a deraileur pivot wear with no (or little) shifting?

Doing my little shifting in lots of rain and mud. Unintentionally, of
course.

--
Phil, Squid-in-Training