Originally Posted by marciero

Another reason to go with 135 vs 145 to get a better chain line with low Q factor on a double crankset. On a double, I would want the large ring located so that it falls in the middle of the cassette. That is how I have my main single bike set up. The small ring is only used for sustained climbs and I want access all the cogs in the back from the big ring without crazy cross-chaining. Doing this with 145 requires much larger Q. Interestingly, people dont seem to comment on this much. My stoker apparently has not noticed!
Separate but related issue-some tandems may not have the chain stay clearance for converting from triple to double and locating the large and small rings where middle and small rings are, respectively, depending on size of rings (again, so large falls in middle of cassette) I considered doing this on our Cannondale and it looks like it would be close.