Originally Posted by SpikedLemon

A good shop should be able to do a basic sizing. Measure you up and, if they have a sizing bike, to set it up to see how you feel in it. (at least my LBS was willing to do this for me). It is by no means considered a "pro fit" or whatever they call it at your LBS.

I'm over 200lbs (I've not measured myself in quite some time) and also tow a bicycle trailer (two kids) with no issues with my Synapse. It's my first road bike but, now that I've had it a few months, I'm quite happy with it and the fit and the bike has not had any issues due to my own personal mass.