Originally Posted by dfcas
Square taper offers the option of different spindle lengths to optimize the Q/chainline/clearance/etc,but BB's are getting harder to find.
Are they really getting harder to find, or is their percentage in the market just getting smaller because the industry has flooded us with tons of different interfaces right now, instead of two or three? If you bike around remote corners of the world and bust a bottom bracket or crank, you'll have a far easier time finding a square taper one.
Nashbar lists FIFTEEN different choices for square taper BB's, including four in its house brand, ten in Shimano (5 different spindle lengths for 68mm!), and one in Campagnolo, versus eight choices for ISIS and four for Octalink.
See this thread:
http://bikeforums.net/showthread.php?t=290371
The only really convincing reason I've seen to ditch square taper is ease of disassembly, which for a tandem, could be a very good reason.