Deore Front Dérailleur Question

Grenouil said:

Ref. my post below on using a Deore front d=E9railleur on a road bikeset-up. I understand that
amount of cage movement for a given cable pull is different for Shimano ATB d=E9railleurs as
compared to their road models. But is it more, or less?

The "mountain" front d=E9railleurs don't travel as far for a given amount=
=20
of cable pull, or to put it another way, the "mountain" units want more=20 cable pull per shift.

If I hadn't already shaved my head, I would have torn my hair out=20 yesterday trying to get an XT
front d=E9railleur on an 1 1/4" seat tube t= o=20 work with road STI and an Ultegra crankset.

This was on a cyclocross frameset that, unfortunately, had top tube=20 cable routing, and thus
required a top-pull front d=E9railleur.

I was able to make it work by grinding away some of the material from=20 the arm where the cable
anchors, thus increasing the "gearing" of the=20 mechanism.

This is further complicated by the fact thas Shimano "mountain" setups=20 are designed around a
47-50 mm chainline, while the "road" cranks give a =

45 mm chainline, so the inward travel of the XT d=E9railleur was only jus= t=20 barely sufficient to
downshift to the small chainring.

By the way, you're the first person I've ever seen who spelt d=E9railleur=
=20
correctly in the French manner in this newsgroup.

Sheldon "Not A Top Pull Fan" Brown +--------------------------------------------+
| If it can't be expressed in figures, | it is not science; it is opinion. | --Robert A.
| Heinlein |
+--------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
617-244-9772 FAX 617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts shipped Worldwide
captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗

Sheldon Brown:

Quoted message said:

If I hadn't already shaved my head, I would have torn my hair out yesterday trying to get an XT
front dérailleur on an 1 1/4" seat tube to work with road STI and an Ultegra crankset.

This was on a cyclocross frameset that, unfortunately, had top tube cable routing, and thus
required a top-pull front dérailleur.

Why did you use an XT fd instead of an Ultegra fd?

"Sheldon Brown" <[email hidden]> wrote in message

url='news:'news:/url... Grenouil said:

Ref. my post below on using a Deore front dérailleur on a road bikeset-up. I understand that
amount of cage

movement

Quoted message said:

for a given cable pull is different for Shimano ATB dérailleurs as compared to their road models.
But is it more, or less?

The "mountain" front dérailleurs don't travel as far for a given amount of cable pull, or to put it
another way, the "mountain" units want more cable pull per shift.

If I hadn't already shaved my head, I would have torn my hair out yesterday trying to get an XT
front dérailleur on an 1 1/4" seat tube to work with road STI and an Ultegra crankset.

This was on a cyclocross frameset that, unfortunately, had top tube cable routing, and thus required
a top-pull front dérailleur.

I was able to make it work by grinding away some of the material from the arm where the cable
anchors, thus increasing the "gearing" of the mechanism.

This is further complicated by the fact thas Shimano "mountain" setups are designed around a 47-50
mm chainline, while the "road" cranks give a 45 mm chainline, so the inward travel of the XT
dérailleur was only just barely sufficient to downshift to the small chainring.

By the way, you're the first person I've ever seen who spelt dérailleur correctly in the French
manner in this newsgroup.

Sheldon "Not A Top Pull Fan" Brown

Sheldon - thanks - I was hoping it was the other way around........

I'm currently struggling with setting up an RSX FD-A417 to work with an RSX compact triple crankset.
I'd like to have used the matching FD-A413, but the frame is an older model Giant TCR with a 1 3/8"
seat tube and a bolted-on bracket for a braze-on dérailleur.

I've ground the curve on the outer plate and increased the length of the slot in the bracket so I
can set it close to the big ring. The problem is that with everything set up so it'll just shift
down to the middle ring, the chain rubs on the outer plate in the big ring with several of the
smaller sprockets. If I increase cable tension enough to clear the chain, it won't shift down.

I've tried changing the angle of the dérailleur, clamping the cable on the wrong side of the bolt
(won't work at all like that), and some judicious bending of the outer plate, with no success.

Maybe I should drill a cable hole through the clamp bolt so I can get a bit more pull - or try
another road dérailleur. I set up an RSX compact crankset on another bike with a Sora FDR and eight
speed cassette with no problem......

I reported:

Quoted message said:

Quoted message said:

If I hadn't already shaved my head, I would have torn my hair out=20 yesterday trying to get an XT
front d=E9railleur on an 1 1/4" seat tube=

to=20

Quoted message said:

Quoted message said:

work with road STI and an Ultegra crankset.

This was on a cyclocross frameset that, unfortunately, had top tube=20 cable routing, and thus
required a top-pull front d=E9railleur.

Jose Rizal asked:

Quoted message said:

Why did you use an XT fd instead of an Ultegra fd?

Onaccounta the frame needed a top-pull front derailer, and Ultegras only =

come in standard bottom-pull configuration.

I considered using a pulley, but couldn't find one that would fit the=20 inch and a quarter (31.8
mm) seat tube.

Sheldon "I Thought Of That" Brown +-----------------------------------------------------+
| If a little knowledge is dangerous, where is | the man who has so much as to be out of danger? |
| --T.H. Huxley |
+-----------------------------------------------------+ Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts shipped Worldwide
captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗

Sheldon Brown:

Quoted message said:

I reported:

Quoted message said:

Quoted message said:

If I hadn't already shaved my head, I would have torn my hair out yesterday trying to get an XT
front dérailleur on an 1 1/4" seat tube to work with road STI and an Ultegra crankset.

This was on a cyclocross frameset that, unfortunately, had top tube cable routing, and thus
required a top-pull front dérailleur.

Jose Rizal asked:

Quoted message said:

Why did you use an XT fd instead of an Ultegra fd?

Onaccounta the frame needed a top-pull front derailer, and Ultegras only come in standard
bottom-pull configuration.

I considered using a pulley, but couldn't find one that would fit the inch and a quarter (31.8 mm)
seat tube.

I have a similar setup, and I use one of the Problem Solvers e-clamp and pulley arrangement which
fits my 31.8mm seat tube.

Interesting that I found out about it from the same inventory database that your related
website uses:

harriscyclery.netpage.cfmOpen ↗
harriscyclery.netpage.cfmOpen ↗

Don't know whether the pulley arrangement makes it harder to shift a bottom pull fd from a top
cable, but I thought it an easier option than modifying an XT fd.

Capt Bike-<< If I hadn't already shaved my head, I would have torn my hair out=20 yesterday trying
to get an XT front d=E9railleur on an 1 1/4" seat tube t= o=20 work with road STI and an Ultegra
crankset. >><BR><BR> << This was on a cyclocross frameset that, unfortunately, had top tube=20 cable
routing, and thus required a top-pull front d=E9railleur. >><BR><BR>

Know you have heard of the shimano e-clamp and roller setup-have you? To use a bottom pull front der
with top cable routing?

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 vecchios.comvecchios.comOpen ↗ "Ruote convenzionali costruite eccezionalmente bene"