Originally Posted by
revchuck
The cassette that's offered with ten speed Tiagra is a 12-30, so it's apparently an answer to SRAM's Apex.
Shimano already had an answer to Apex: the cross compatibility between mountain and road rear derailers took care of that. (The front, of course, are not cross compatible.) My CX bike runs a 105 group with a Deore LX rear derailer. Problem solved.
Unless the new shifters are no longer cross compatible...