Equinox

I've had it for four years and no one can seem to adjust this thing. When I'm in the big ring and the smallest cog, the outer plate rubs. It is not because it is at its limit because if I pull the cable, the derailleur moves away from the chain. When I'm in the middle ring and I try to use the largest 2 or 3 cogs, the FD will auto-shift to the smallest ring. Shifting from the middle ring to the big ring is hit or miss.
It sounds like the cable is too loose. When I get it back from the shop after they adjust it, it will shift great for about five miles and then it reverts to the same old problems. Is it possible for the problem to be related to the in-line barrel adjuster? When it starts to screw up, I can fix it a little bit by playing with the barrel adjuster. I know that you shouldn't have to do that one it is adjusted. It just seems like the cable stretches really fast. Should I try replacing the barrel adjuster or maybe take out the inline and replace it with the regular kind?

fietsbob

<guess> you writing at work computer?

I Cant see a thing ,, drop it by a shop.

Drive train parts may be worn cables may be out of adjustment stiff grease in the brifter , many possibilities.

cderalow

might be better posted in the tandem forums.

I know there's a long standing issue with getting them adjusted just right.

Wilfred Laurier

what shifters do you have
and are you sure you have compressionless sis style cable housing

Wilfred Laurier

oh
also
what crank and chainrings do you have

because I had a fsa crankset and rings
that always dropped into the small ring when in larger cogs

get some shimano rings
if you dont already
and be happy

Retro Grouch 

From your description the first thing I would look at is the cable housing ends. If you can see a stray wire or two sticking out - that's it! Remove the ferule from the end, cut the housing nice and square and you'll be good to go.

If your housing isn't square, it will gradually shorten itself during use. When that happens you can adjust the shifting to work right for awhile but, after some period of time, it reverts back to inadequate cable tension.

Andrew R Stewart 

The challenges of Shimano STI shifting on Tandems is why some teams convert to bar end levers. When I worked in a tandem shop (for 7 years) we had constant issues with even new bikes. Everything had to be Just So. The more matched the system was the better things went. Still the tandems we set up with Campy Ergo or end levers had MUCH less complaints. Andy.

zonatandem

Agree with the above post!
Have used STI and have used Di-2 shifting on our tandems. While barcons are not the latest hi-tech they are reliable and precise.
Pedal on!
Rudy and Kay/zonatandem

Andrew R Stewart 

Hey Rudy- Glad to hear that you're still with us. I've read your posts for many years and hope that can still be tandeming when I am as old as your are. Andy.

WPH

I have a tandem that uses STI (Ultegra 9sp for the rear, Tiagra 4400 triple for the front) on Truvativ cranks and rings and the whole thing works very nicely. It was easy to set up, functioned correctly from the beginning and has never needed much fiddling to keep in good order. I have not used other STI triple shifters apart from this old used Tiagra unit, but it seems to have a bunch of stops and trim positions which allow one to always find a FD position that works. STI has a place on tandems. I am keen to try 10sp.

On the other hand my Scott (Dura Ace 7800 10sp groupset) came new with inline cable adjusters and until they were removed was always giving me the irrits. I would get everything - front and rear - working well but after an hour on the road gear changes would start to get sketchy and after 100km the chain would be nearly one gear behind at the back and would refuse to get onto the big ring no matter how hard I whaled on that left hand lever. That bike is now 40-50,000km old changes reliably when new cables etc are installed and correctly adjusted.

My experience is that inline barrel adjusters unwind due to road vibrations. Some unwind quickly, others take a week or a month or more. I have never had one that would stay set for any length of time. I think the ones I have used have been Shimanos, perhaps other brands (I think Jagwire do them too, for example) might be more reliable. Conversely I have never had a problem with conventional frame or derailleur mounted adjusters, regardless of the brand.

The front derailleur on a tandem is not much further away from the shifter than a rear derailleur on a single bike and we now expect to get 11sp working well on singles, it is reasonable to expect reliable changing on a tandem triple.

Anyway, post a picture of you and your stoker and the bike on the happy tandem couples thread sometime!

DMF 

Good post, WPH.

I don't see the "unwinding [down tube] barrel adjusters". Are you using the ones with the detents? Those would seem to be pretty difficult to move.

Dennis

Equinox

I'll post a picture after I get this thing shifting right. I am really suspicious of the in-line barrel adjuster, and I think you are are right. My concern is that the cable guide on the frame where you would put a barrel adjuster does not have much clearance from the frame. I don't think most of the frame mounted barrel adjusters I've seen would fit because of their diameter. Can you get barrel adjusters with a lower profile? And BTW, my in-line barrel adjuster does not have detentes.

Andrew R Stewart 

We install in line adjusters frequently, the lack of OEM adjusters is just WRONG. We have not seen the self loosening cable tension with these adjusters, and I usually grease the threading/spring because I have seen corrosion freeze these tight. But we do try to pick a section of casing which doesn't have too much curve to it but also not rattle against the frame. We also try to use the provided (Jagwires) housing stops which are a touch tight fitting in the adjuster. Andy.

Equinox

I believe mine is the Jagwire "Rocket" adjuster and it is in contact with the frame. It's actually scratching the paint.

Equinox

That issue with placing a frame mounted barrel adjuster: Is it possible that the cable guide could be too close to the frame so that there would not be room to install a barrel adjuster? Could that be the reason there is an in-line adjuster in the first place?

WPH

Yep, probably the reason.

But there are different designs for frame-mounted barrel adjusters - some are fatter than others. The issue is whether the cable stop on the frame has a thread which will mesh with the barrel adjuster. If the cable stop is metal you could drill the hole out to 5mm and then tap the hole (tap set $10 if you are lucky). Then use any sort of barrel adjuster that fits, the type from an old Shimano RD is low-profile.

It is possible to run a FD without a barrel adjuster, lots of bikes worked this way in the old times. The difficulty arises if the inside FD limit stop doesn't get the cage outboard far enough when the cable is at its least tense. This is where the barrel adjuster can help a lot: clamp the taut cable in the FD then wind the adjuster out to tighten the cable even more and pull the cage further out.

WPH

Retro Grouch 

OP didn't specify what kind of bike.

Santana, of the 160 mm rear triangles, uses somewhat wider BB spindles to get the right chainline. At one time at least they had a gizmo to relocate the front derailleur a little farther out on the seat tube.

loimpact

In my ignorance, I have to ask.......

Why would bar end shifters/levers make any difference in the precision of shifting in comparison to brifters (or downtube/stem/etc) when properly adjusted???

mibike

With bar ends the front shifting is friction. With Campy the front is micro clicks so it's almost like friction that won't slip. With either system all you need to do is set the high and low limits no cable adjustment needed. I have used bar ends and have them on my touring bike. I now use Campy and have them on my singles, tandems and triplet. They both have good shifting front and rear. I have tried STI and was never happy with the front shifting. I think STI front shifting is one of the reasons a lot of riders don't like triple cranks.

Andrew R Stewart 

That last sentence is telling! This brings new light to the market shift from triples to compact doubles (that I first saw back in 1973 on Gitane touring bikes...). So because the Shimano choice to use Indexed front shifter designs is why triples are becoming extinct? I will discuss this with my coworkers again. Andy.

mibike

I don't think it's the only reason but one of them. If you discuss this with your coworkers I would be interested in their opinions.