Originally Posted by
cyccommute
He doesn't need a NOS 8 speed montain bike rear derailer. He just needs a mountain bike derailer that isn't Dynasys. A new Shimano SLX and lower would work as would a one to two year old non-Dynasys XT or XTR level. These dereailer play real nice with STI shifters.
Shimano's website seems to claim that for 2013 virtually everything they sell, including SLX and Deore, is designed for 10-speed Dynasys drive-trains. I didn't read the spec sheets for every RD they sell, but a quick glance at their website seemed to suggest that the 9-speed Alivio group was the only non-Dynasys hold-out. Altus, Acera and the other ultra low-end 8-speed groups aren't mentioned at all, however. I'm assuming they're still available, though I'm not sure I'd want to trust them for a touring bike.
And that
still doesn't change the fact that a road bike with a short wheelbase won't make a great touring mount...