Wow...lots of information here. I wish I had some information to give back. If memory serves correct the Trek is a 2007. But, I really don't know what model the Synapse is.

I'll go into the bike shop this weekend - the owner, a woman who started the shop 40 years ago, has been good to work with so I can only hope that will continue.

Do you think it would be an option to put a 3-ring on the Synapse? Or is there something about the frame of the bike that makes it designed to only accomodate a double?