The wife and I have a new Cannondale road tandem and I have been struggling to get the front derailleur adjusted properly. It has Ultegra 9 speed brifters, an Ultegra triple front derailleur, a Deore XT rear derailleur, and Truvativ tandem cranks.

It came from the LBS marginally adjusted. The LBS guy said that I have to click down twice to get from the largest to the middle chainring. IE the first full downshift just rubs, and I have to use the middle trim to actually shift to the middle ring.

I'm no stranger to bicycle mechanics, and I've installed my share of parts (between the wife and I, we have 7 bikes). I've done the indexing front deraileur thing on my Deore XT mountain bike, and my wife Deore XT hybrid (two different era of XT). My wife's road bike has RSX brifters and 105 components. I've got all those working perfectly, but this one has me ripping my hair out. Here's the symptoms:

It appears that the front derailleur does not move enough from inner to outer. i have carefully followed Shimano's alignment tech note (as well as tried some of my own tweaks to it). If I adjust so I can downshift from largest to smallest chainrings properly, the deraileur doesn't move outward enough on the largest chainring and the smallest three rear cogs rub (on a tandem we use these to bomb down hills). IF I set the deraileur so upshifting and the largest chainring adjustment works well, I can't downshift well. I get the double tap to get out of the largest chainring, and I can't reliably get into the granny ring. It's like I don't have enough throw, and I can skew it to the inside or the outside.

Ideas and things I've tried:

- checked the outer cable to make sure it's not flexing
- checked the outer cable ends to make sure they are well seated in the frame braze (weld) ons
- checked the bb routing plastic thing to make sure it's not flexing under the tension.

Suspicions:

I am not impressed with the Truvativ cranks, the chainrings on the timing chain portion do not run true, and my efforts to true them up haven't been very successful, there just isn't enough adjustment room in the chainring bolt holes. I'm wondering if the chainrings for the derailleur chain are slightly wider spaced than they should be. I've done some preliminary measuring and they don't appear to be set farther apart, but on the bike, it's hard to get a good measurement.

I'm also thinking that the front derailleur cable could be stretching a little as the very strong front derailleur spring loads up the cable. I need to check this theory out with a sharpie and a machinist's scale. The cable is miles long on this bike, and the front derailleur cable is under more tension than the rear, so this seemed to be viable option.

It could be that I'm just an idiot, but the LBs couldn't get it any better than I have it.


Needless to say, I have to find a solution to this. My scorched earth solution is to toss the brifters in the trash and put bar ends on. The concept of indexing front derailleurs is silly IMHO. But I'm a pre-indexing campy riding guy. It would be nice to find a solution to this problem. Any tips and tricks would be welcome.

Sheldon