Originally Posted by
LongVehicle
Sorry, by double shift I do mean shifting both the front and rear at the same time (to the smaller ring and a smaller cogthe XTR 11-36 is spaced to make these shifts similar to simply shifting to the next larger rear cog). I'm using Ultegra STI 6770 shifters, the FD6770 where I replaced the actuater screw to push the shift farther outboard (with the stock screw the motor won't reach out far enough but the design of the pivot points of the derailure cage itself could reach), and a modified RD 6770 from K-Edge. The shifts to the larger ring are fine, great in fact, but on occasion without the double shift (front and rear) the chain won't drop to the smaller. I'm currently running Ultegra 53/39 rings (and the 36-11 cassette).
Some ideas to try (if you haven't already):
Shift while your cadence is reasonable. Lower cadence generally means more tension on the chain and that hurts shifting. I know this can be difficult. It helps if you can really shift the back and front at the same time. If you get the timing down it works well.
Since you are only running two rings up front, a) install a chain catcher just inside of the inner ring. b) adjust FD and FD inner stop for an aggressive shift to small ring and rely on chain catcher to prevent the chain going inside of the small ring. I used to do this on a cyclocross bike with non indexed left bar end shifter and I could just slam the shifter all the way and the FD cable would go completely slack.
Angle the FD ever so slightly so that the leading edge is inboard of the trailing edge. This helps it guide the chain off the big ring. Just enough so you can barely see it. Too much and you will have more chain rub. Sorry to those that have a braze on FD with no rotational adjustment.
Run a little longer chain. a longer than usual chain length on road bikes will result in a little less chain tension and slightly better shifting to the small ring.
Keep chain very well lubed. Regardless of lube used a well lubed chain slides easier off the big ring.
Change you chain line in a little. - This may not be possible since I think you have external BB bearings, but it is one approach.
My approach is to do most of the above and use 1999-2006 Campy left shifter. Amazing how much more load I can shift under with that shifter. I don't call out shifts to inner ring and my stoker just keeps pedaling right through it. I know this is probably not one you will want to do but it may apply to others.
Good luck - oh and if you want to get electronic shifting then get it. That would work too.