Help me come up with a ballpark idea of roadbike frame size for me

[VeloVT]

what works for one may not work for another... body proportions, fitness & flexibility, riding style, position preference and differences in frame geometry all come into play...

but... I am similar in size to you (5'6" and 31.5" inseam) and I can make frames between 49ish and 52ish work with fairly standard length and rise stems. My current road bike is a Scott CR1 Pro size XS. It's 49cm, and I'm running a 120mm, -6deg rise stem. I have two spacers under the bars right now, so I have the option to drop the bars a little, which I'm considering doing, but overall the fit is good. My bf's bike is a 52 with a 100mm stem and a bit less drop and I'm comfortable on that too, and my commuting/all around bike is a Bianchi Axis 52cm with a 90mm stem with significantly more rise than the other two bikes, and it's super duper comfortable -- I could spend all day on it.

Some people my size ride bigger bikes though, I think.

[MartianDestiny]

Use the geometry of your old bike as a baseline (assuming you are happy with fit there).

The geometry of the 08 version is here: http://www.giant-bicycles.com/en-US/...llections_id=3

Drop bars make the reach a little longer than most flat bars, so you may wan to go slightly shorter on the top tube.

Your best bet is to use the above geometry ("size" and effective top tube length mainly) to weed out bikes and then shop locally so you can still go try them out and confirm fit.

[VeloVT]

Also, lots of shops have a nifty laser fitting booth that calculates a frame range for you after the salesperson takes a few data points.

You're a common enough size that they should have a fair amount in stock that will fit you -- your best strategy may be to just start visiting some shops and testing some bikes.

Edit: Oh, I just reread your post and realized you are looking at Ebay/Craigslist... Hmmm... it still might not be a terrible idea to go to a shop and talk to them a bit.

[aicabsolut]

I'd guess due to your relatively shorter legs that a 49/50cm frame in standard geometry might work. Possibly a 52.

I'm 5'7" with a 32.5" or so inseam. I ride a 54cm road bike with a 54.8cm top tube length a 110mm stem (that's pretty much level to the ground--not sure about angle)

[Trek420]

Edit: Oh, I just reread your post and realized you are looking at Ebay/Craigslist... Hmmm... it still might not be a terrible idea to go to a shop and talk to them a bit.

It's not a terrible idea, it's a great idea!

Many shops carry used bikes, my LBS will re-sell bikes for select clients on consignment (he has a sweet custom painted Rodriguez unless it's been snapped up), they sell customer returns and exchanges, last years model (does it really matter if it was last year? let's snap those up!) they will sell from a rental fleet if they rent etc.

Is there a Bikeswap in your area? Check that for great deals often again from ..... drumroll .... your LBS.

In this economy we need to support our LBS. There are some great deals out there and you get all the service of the shop.

[sundial]

LoriO, you will probably fit a medium, size 53-54.