MTB front derailleur on road bike problem- NOT indexing issue

Dan Daniel said:

I changed my chainrings to 46/36/26 and tried installing an
XT front derailleur, thinking that its profile would match
the chainrings better and give me better shifting.

I am using barend shifters so indexing is not an issue.

Both the XT and the existing derailleur are bottom pull,
bottom swing.

But the cable attachment point is further to the inside on
the XT than on the old road derailleur (RSX or RS100, can't
remember and the label is gone).

So when I go to shift, the end of the cable attachment arm
hits the fender. I can't move the fender back any- it's
already too tight to remove the wheel without deflating it.
This is a bike with 42 cm chainstays.

On another bike with much tighter geometry, I ran into the
same basic problem. I was able to use it because that bike
has no fenders, but the cable arm is very close to the rear
tire. I doubt I could use a larger tire- 23mm right now.

Is this typical for all MTB derailleurs? Or is it specific
to bottom pull, bottom swing designs? Would a bottom pull
top swing avoid this problem? Or some model other than XT?
Any experience mounting MTB models on road bikes much
appreciated.

You should get a "traditional" top swing front derailleur.
As a bonus, you can get an LX designed for 48 tooth rings
(or an XTR for 46, or an XT for 44). All but the XTR are
relatively cheap too. It'll probably have to be special
ordered though.

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of
the $695 ti frame

On Mon, 28 Jun 2004 22:04:26 -0700, Mark Hickey <[email hidden]>

Quoted message said:

Dan Daniel said:

I changed my chainrings to 46/36/26 and tried installing
an XT front derailleur, thinking that its profile would
match the chainrings better and give me better shifting.

I am using barend shifters so indexing is not an issue.

Both the XT and the existing derailleur are bottom pull,
bottom swing.

But the cable attachment point is further to the inside on
the XT than on the old road derailleur (RSX or RS100,
can't remember and the label is gone).

So when I go to shift, the end of the cable attachment arm
hits the fender. I can't move the fender back any- it's
already too tight to remove the wheel without deflating
it. This is a bike with 42 cm chainstays.

On another bike with much tighter geometry, I ran into
the same basic problem. I was able to use it because that
bike has no fenders, but the cable arm is very close to
the rear tire. I doubt I could use a larger tire- 23mm
right now.

Is this typical for all MTB derailleurs? Or is it specific
to bottom pull, bottom swing designs? Would a bottom pull
top swing avoid this problem? Or some model other than XT?
Any experience mounting MTB models on road bikes much
appreciated.

You should get a "traditional" top swing front derailleur.
As a bonus, you can get an LX designed for 48 tooth rings
(or an XTR for 46, or an XT for 44). All but the XTR are
relatively cheap too. It'll probably have to be special
ordered though.

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home
of the $695 ti frame

Oh [censored].... I meant top swing all along maybe? Meaning that
the clamp band is above the pivot arms, yes? Traditional as
in what every road derailleur I have ever seen looks like
(although now I see bottom[clamp below or on level with
pivots] swing front derailleurs some places). Well, this is
what I see called a top swing- cambriabike.comshiftOpen ↗
&der/shimano_deore_xt_m760_front_derailleur.htm

That is NOT what I have.

THIS is the style I have- cambriabike.comcambriabike.comOpen ↗
shimano_lx_m571_front_derailleur.htm

although the XT version of it. Where the cable clamps, that
point is maybe 5mm further to the center of the bike on the
XT than on the RSX/RX100 and two 105s that I have. It is
this displacement of the cable anchor point that causes the
arm to hit the fender when I shift up.

Since you and I might be backward in our names here, do you
mean that I should get a front derailleur like the XT 760
shown above- clamp below or in line with the cage? That this
style will be less likely to interfere as it travels inward?

(And do you really see that style as the traditional? From
your web site, I must admit that I see you as old enough to
remember a day when that [censored] MTB low-down clamp thing
didn't exist 🙂

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

Quoted message said:

Mark Hickey said:

Dan Daniel said:

I changed my chainrings to 46/36/26 and tried installing
an XT front derailleur, thinking that its profile would
match the chainrings better and give me better shifting.

I am using barend shifters so indexing is not an issue.

Both the XT and the existing derailleur are bottom pull,
bottom swing.

But the cable attachment point is further to the inside
on the XT than on the old road derailleur (RSX or RS100,
can't remember and the label is gone).

So when I go to shift, the end of the cable attachment
arm hits the fender. I can't move the fender back any-
it's already too tight to remove the wheel without
deflating it. This is a bike with 42 cm chainstays.

Oh [censored].... I meant top swing all along maybe? Meaning
that the clamp band is above the pivot arms, yes?
Traditional as in what every road derailleur I have ever
seen looks like (although now I see bottom[clamp below or
on level with pivots] swing front derailleurs some
places). Well, this is what I see called a top swing-

cambriabike.comshimano deore xt m760 fronOpen ↗
t_derailleur.htm

Quoted message said:

That is NOT what I have.

Quoted message said:

Since you and I might be backward in our names here, do
you mean that I should get a front derailleur like the XT
760 shown above- clamp below or in line with the cage?
That this style will be less likely to interfere as it
travels inward?

I'm nowhere near the expert Mr. Habanero is, but if this
were my bike, I'd do one of two things: -cut the fender out
where the derailleur is gunking things up. If the problem is
that far down the frame it's not going to get your bike or
your self much dirtier to lose that bit of fender. -try out
a bottom-swing front derailleur.

I know this smacks of "take it to marketplace," but I have
an XTR BP/BS 1
1/8 if you want to try it. It has been mounted and setup was
attempted - so there have been a few workstand shifts -
then I realized I was a moron trying to get 105 shifters
to work it correctly. So, it's essentially new. I'll send
it to you for $20. Here's a pic: cambriabike.comshimano xtr mOpen ↗
952_front_derailleur .htm

Chris

Dan Daniel said:

Oh [censored].... I meant top swing all along maybe? Meaning that
the clamp band is above the pivot arms, yes? Traditional as
in what every road derailleur I have ever seen looks like
(although now I see bottom[clamp below or on level with
pivots] swing front derailleurs some places). Well, this is
what I see called a top swing- cambriabike.comshifOpen ↗
t&der/shimano_deore_xt_m760_front_derailleur.htm

That is NOT what I have.

THIS is the style I have- cambriabike.comshift&derOpen ↗
/shimano_lx_m571_front_derailleur.htm

although the XT version of it. Where the cable clamps, that
point is maybe 5mm further to the center of the bike on the
XT than on the RSX/RX100 and two 105s that I have. It is
this displacement of the cable anchor point that causes the
arm to hit the fender when I shift up.

Since you and I might be backward in our names here, do
you mean that I should get a front derailleur like the XT
760 shown above- clamp below or in line with the cage?
That this style will be less likely to interfere as it
travels inward?

(And do you really see that style as the traditional? From
your web site, I must admit that I see you as old enough to
remember a day when that [censored] MTB low-down clamp thing
didn't exist 🙂

You've probably already got as good a FD as you're going to
get for your dilemma... you have a 'traditional top swing'
FD. Probably time to trim the fender.

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of
the $695 ti frame

Chris said:

Quoted message said:

I'm nowhere near the expert Mr. Habanero is, but if this
were my bike, I'd do one of two things: -cut the fender out
where the derailleur is gunking things up. If the problem
is that far down the frame it's not going to get your bike
or your self much dirtier to lose that bit of fender.

I've thought of this. Don't like it, but it might be the
answer... IF the arm will clear the tire. Once it hit the
fender I stopped checking.

Quoted message said:

-try out a bottom-swing front derailleur.

I'll borrow an old one from a friend and see what happens.

The terms are getting to me 🙂 The XTR-952 you have is
called 'top swing' on the Cambria web site and the
Shimano site-

ike.shimano.com/mtb/XTR/componenttemplate.asp?partnumber=FD-
M952

Quoted message said:

I know this smacks of "take it to marketplace," but I have
an XTR BP/BS 1
1/8 if you want to try it. It has been mounted and setup
was attempted - so there have been a few workstand shifts
- then I realized I was a moron trying to get 105
shifters to work it correctly. So, it's essentially new.
I'll send it to you for $20. Here's a pic: cambriabike.comshimano xtr mOpen ↗
952_front_derailleur .htm

Chris

Hmmm... very tempting. Thanks for the offer. Let me do some
more experiments and I might take it off your hands.

Mark Hickey said:

You've probably already got as good a FD as you're going
to get for your dilemma... you have a 'traditional top
swing' FD.

You're getting your terms confused, and it probably doesn't
help that the Cambria Bike page showing the conventional LX
derailleur also mistakenly describes it as 'top swing'.

A 'top swing' derailleur clamps to the frame below the
parallelogram. A traditional, 'normal swing' or 'bottom
swing' clamps to the frame above the parallelogram, and
that's what Dan has. 'Traditional top swing' is a
contradiction.

A top swing derailleur is less likely to foul the mudguard
than the one Dan is using currently.

James Thomson

Dan Daniel said:

Is this typical for all MTB derailleurs? Or is it specific
to bottom pull, bottom swing designs?

MTB derailleurs have a longer arm (and hence require more
cable pull) than road ones, so conventional (bottom
swing) MTB derailleurs like yours are more likely to foul
a mudguard.

It's generally not a problem for 'top swing' or top-pull
derailleurs, because they have the lever arm in a
different place.

Quoted message said:

Would a bottom pull top swing avoid this problem?

Yes, almost certainly. I used a bottom-pull, top-swing XTR
950 model to get around this problem on my touring bike.
The cable pulls the clamp down and to the right, away from
the mudguard.

James Thomson

James Thomson said:

Dan Daniel said:

Is this typical for all MTB derailleurs? Or is it
specific to bottom pull, bottom swing designs?

MTB derailleurs have a longer arm (and hence require more
cable pull) than road ones, so conventional (bottom swing)
MTB derailleurs like yours are more likely to foul a
mudguard.

It's not just that it's longer. It is angled further to
the center of the bike compared to a road FD, and so it
starts closer to the tire than the road FD. But whatever
geometric changes lead to the problem, it is definitely a
problem for me.

Quoted message said:

It's generally not a problem for 'top swing' or top-pull
derailleurs, because they have the lever arm in a
different place.

Quoted message said:

Would a bottom pull top swing avoid this problem?

Yes, almost certainly. I used a bottom-pull, top-swing XTR
950 model to get around this problem on my touring bike.
The cable pulls the clamp down and to the right, away from
the mudguard.

James Thomson

Ok, thanks. How has the top swing held up? Looks likes a lot
of pivot points for slop and wear.

I have a top swing bottom derailleur on another bike- an
Alivio. I made some rough measurements as to how far back
the pivots go from the down tube and the relations between
the pivots and the chainrings. All in all- doesn't look very
hopeful! But my frames aren't true touring with long
chainstays. Putting it in place would be the only sure
answer. Then I'll go by the LBS and see if other model
derailleurs have less rear projection.

Looking at the XT derailleur, looks like I could move the
cable clamp to the inside/front and gain 4 mm or so.
Hmmm.... use a pan head bolt in place of the allen and looks
like no interference between the bolt and clamp..... I knew
there were reasons I liked not having indexing on the front!
This is the kind of thing that will send me to Campy if I go
to brifters.