Originally Posted by
kayakdiver
There is zero compatibility issues running Tiagra STI shifters with a touring crank set. For that matter they work fine with 10 speed. Just need a compatible FD like Tiagra. The RD doesn't care what shifters you are running. Run a Tiagra FD and it will work great. No friction required.
I've run XT RD's with Ultegra 10 speed systems for extreme climbing when I wanted to use an 11/32 RD because I needed the wide gear swing that my DA RD can't handle.
What I'm trying to say is that most of this stuff will work and work well together.
In my experience, the Ultegra 10 speed
FD is too long to work acceptably with a "touring" crankset. I haven't tried a Tiagra 10 speed FD, but I would have my doubts. The XT FD doesn't work with the Ultegra 10 speed shifters either.
http://sheldonbrown.com/harris/derailers-front.html
I haven't heard whether the IRD Alpina-d front der works with the Ultegra 10 speed. If so, then the new 10 speed MTB cassettes would indeed give tourers new (modern?) STI options.