triple setup troubles
 

I am having trouble making a triple setup work on my Rivendell Sam Hillborne.
I am trying to use a Specialized "Flag" triple crankset and a Deore XT FD and Shimano barend shifters (set on friction.) [ Deore XT FD seems to be the Go To FD choice for Rivendell riders.)

I have I think followed the standard FD setup steps.
- in Small Front/Big Rear set the limit screw to just allow the chain to clear.
- set the FD cages basically parallel to the chain rings
- allow a coin's thickness height clearance of the cages over the big ring.
- while the Specialized "Flag" triple crank is not in Sheldon Brown's database of compatible Cranksets and BB I think I used a 117mm axle BB and the small ring seems to just be clearing the chainstay reasonably.

But I cannot seem to get enough "throw" to both shift into the big chainring AND to drop down into the small ring.

Now, maybe just dipping into my parts bin for parts I think should work has left me again with incompatible components.
But I understood that a LH barend shifter should have enough range to cover a triple shift.
https://cimg5.ibsrv.net/gimg/bikefor...76fdd97d25.jpg
https://cimg6.ibsrv.net/gimg/bikefor...4ef10f148e.jpg
https://cimg8.ibsrv.net/gimg/bikefor...c1405c7671.jpg
https://cimg9.ibsrv.net/gimg/bikefor...7bab5f8c27.jpg
https://cimg0.ibsrv.net/gimg/bikefor...5cd2343f12.jpg

I think I had the same crank on my 86 Rockhopper? IIRC, it took more like 122 or 127??
Memory is too foggy.
Can you get it to shift off the chain in either/both rings if you back off the limit screws? You "should" be able to if the shifter has enough throw.

BTW- "mountain" FDER's use a different cable pull than "road". I'm ignorant about "road" stuff, but I wonder if a bar end (road) shifter has enough throw to move a mountain triple the full range needed?? If designed for a double only????

First thing I'd try is detaching the cable and backing the low limit out until (hopefully) the derailleur is sitting centered on the little ring.

if I play with the H and L Limit screws I can get it to EITHER handle the Middle and Big OR the Middle and Small.
but I am struggling to get it to handle all three, at least not gracefully. there just doesn't seem to be enough cable throw to span the three rings.

By Gracefully, I mean that at times (as I have fiddled around with cage alignment and limit screw settings) I have been able to get it to drop into the small ring but ONLY if I come flying off the Big ring. as if momentum carried it from B > M > S.
but if I am in the middle it won't drop down to the small.

How does axle length affecting shifting performance? I would have thought that if the small ring clears the chainstay and the FD didn't bump into the seat tube at its most inside, then axle length would be irrelevant. (but I am probably wrong.)

Hmm, I guess I've only tried Suntour power shifter barends with MTB front derailleur, but they had plenty of throw. It is entirely possible that these barends don't have enough pull to shift a MTB triple.

It was a question to see if the FDER "travel" is "centered" over the rings instead of "offset" to one side or the other like an improper spindle length would do.
IF you can drop it off BOTH rings, centering is not an issue.

Oh, and upon attaching the cable make sure the derailleur didn't move, because if it got pulled outboard even a little bit while cinching the cable anchor bolt, the travel will be limited by the too-tight cable.

Centered. hmmmm, I thought the correct small ring limit setting (is it Low or High? I though the easier gearing was the Low Limit but Leonard Zinn calls it the H-Limit screw) was so the chain just cleared (on the inside) when in the Small Front, Biggest Rear, i suppose so as not to waste travel range.

But Hey, I'll try centered. tomorrow (it's pitch black here) and report back.

Yes, I wonder that too. As I have run into the same compatabiliy issue in reverse on another bike: MTB LH shifter not working well with a Road Triple FD.
but this - barend LH with MTB FD - seems to be the Go To setup for Rivendell riders.
and I asked a knowledgable person who though that a LH Shimano barend should have enough range to cover a triple crankset.

it's usually approx centered over ring with 3x8 mtb but yeah set it so the chain doesn't drag on the inside plate in the little ring/big cog combo, bit just barely.

Sometimes just barely not dragging won't allow the chain to drop to small ring very easily, so you might need a little more space between chain/inside plate

IF that crank is as old as I think, it'd be from the 6 speed MB era. I never paid attention, but maybe that spacing is just a bit wider than "road"?
Possibly that specific shifter (assuming it's the Dura Ace oddball) just doeasn't "quite" have the span of other Shimano bar ends?
Were the people using barends using SunTour possibly?

are those shifters ultegra 8 or 9spd? either way, they really should have enough throw. my 8spd shifters work fine with a deore dx triple FD and crank that has quite a wide q-factor. maybe try an alternate cable routing as folks do with road STI and mtb triple fronts. wrap the shifter cable up underneath the pinch bolt vs over the top of it.

incidentally, why are you showing a picture of the right hand shifter? also, it looks like you have the cable routed from it to the FD. right hand shifters are for the rear. it says "compatible with RD 7400", etc...meaning Rear Derailleur

I hate the hammer approach, but I've read here of people squeezing the middle of the cage together SLIGHTLY to help it ease the chain over a tiny bit more.

Do you have the cable run under or over the tab at the pinch bolt? Should be over.

it's over the pinch bolt in the picture, but that ain't his problem. it really looks like he's using the rear shifter for the front derailleur

there is no label on the LH shifter so I didn't think it added any information. But since the RH is Dura Ace I believe the LH is also Dura Ace.
I just showed the photo of the RH to show the style of shifters - i.e. Shimano. but not Suntour.

Ummm, the cable is running OVER the top of the pinch bolt body if that is the question. (I don't know what the "tab" is)

No sorry, I have a correct LH shifter on the LH side but since there is no label on it I included the label of the RH shifter as that at least seems to narrow it to Dura Ace. 7700/7800
but I assumed that the LH was pretty "dumb" not indexed and so should work. IF it has enough range. Maybe DA was never meant to handle a triple. that would make sense. (but it was all I had that would do 8S in the rear)

that could be my problem. if that LH DA is designed only for 2X

oh....so do you have the cables crossed underneath the downtube, then?

Yes, I have the cables crossed under the downtube.
(I think it gives the cable housing a nicer look.)

i've done that, too. i'd read somewhere that routing had created issues for the poster, but he didn't specify the problem. at any rate, if it's not been a problem for you in the past, then it's a moot point. i would try the alternate cable routing....under the pinch bolt vs over. it works for the brifter crowd. couldn't hurt

l used that derailleur with a 9sp Dura Ace bar end on a triple and it worked perfectly. Are you setting the shift cable tightly with the FD on the small ring? I needed less than 90 degrees of travel to shift from small to big ring.

Where did you get that FD? I bought mine in 1990, retired it a couple of years ago.

If the issue is 'not enough cable travel', then this will help. Routing on the underside, closer to the piviot point of the arm will more closely mimic the shorter pull ratio of older road FD.

Another thing to check is if the FD had a spring adjustment hex screw. See the attached pic. This adjusts the return spring tension of the cage. Another thing that was needed to be adjusted in the early brifter days.

https://cimg5.ibsrv.net/gimg/bikefor...02491dc749.jpg
FD-M550 LX Tension adjuster

I’m not familiar with bar end shifters. I know that downtube shifters have no stop that limits the degree of throw when shifting to the large ring. I’ve run MTB front derailleur with no issues.

Is there a stop, on the bar ends, that limits the amount of throw in when shifting to the large chainring?

Can that stop he modified to extend the degree of rotation?

John

If you haven't, you might check the alignment of the derailleur cage to the chain to make sure its straight.

Also, if you have barrel adjusters, you might want to experiment with the tension.

You might have two much high from the cage to the chainring - depends on which "coin" you are using. If i'm not mistaken, my 105 FD instructions called for about 1mm of clearance from tooth to cage. Most of my issues went away when I fixed that

best of luck and nice bike - I love Rivendells