Good luck with that angle. Around here it is very common to see posts where the seller will say they won't hold an item due to too many no-shows. Ads with email contact are always a game, sometimes you'll get a fast response, sometimes all their emails will go to their spam filter due to the craigslist email address aliasing, and sometimes the sellers won't check their email until certain times of the day. I had one recently where I tried emailing the seller during the day, then sent another email the following evening from home, and finally a few days later the guy called since I put my cell phone number in my email to his CL forewarder. You pretty much have to be ready to go see it as soon as you get a response, or set up a time with a request that they call you if someone else shows up first.

Funny, I find a whole lot of bikes and frames that are toooooooo big.