Originally Posted by
HarborBandS
This is the primary reason I wouldn't consider the Tiagra version of this bike. Once you are stuck in 10-speed land, it becomes prohibitively expensive to upgrade components, since you would need new hydraulic brifters to go up to anything 11-speed (105, Ultegra, or DA). But with the 11-speed 105 included on the SL5, you could incrementally upgrade individual components to Ultegra/Dura Ace as they wear out or break, or if you are running out of ways to shed grams.
But of course, 12-speed may be on the near horizon anyway...
Based on very faint murmurs I have heard on the internet, I think next gen Tiagra may still be 10 speed. At the very least, Sora would be 10 speed, and it is not bad at all. Hopefully proper hydro disc trickles all the way down.