I must be built funny.

[OakLeaf]

I'm also wondering what the issue with your knees might be.

It's true that only the smallest complete bikes come with cranks shorter than 170mm, but that's a crank swap, not a frame issue (and it's a swap I had to do on my 50cm C'dale).

If you're having trouble finding a frame with a short enough TT, but seat-wise you can fit on a larger frame, consider just buying a smaller frame and an uncut fork. Then you can set the handlebars and seat where you want them in relation to each other. Not the most inexpensive thing in the world but a whole lot cheaper than a custom frame!

If you're more specific about your proportions I bet there's someone here who can suggest a frame for you.

[Owlie]

Muirenn, I'm a hair shorter than you (5'6-3/4"), and I have the same problem you do. I need a pretty short top tube, and even some WSD bikes are too long.
My Giant is a 50cm/M, but they run big, by the looks of it--and the Avail's geometry isn't terribly different from the Defy.

My knees weren't terribly happy with the test rides, but that may well simply be because the seatpost was adjusted to "eh, close enough" and I have crappy knee ligaments. If it were properly adjusted (ie, when I'm actually serious about buying), it might well be a different story. It felt good otherwise (even better than the Treks), so I'm still keeping it on my "list"

I did in fact try out a Quest Femme (lovely bike), but I'd need a 54, and that's something that the shop doesn't stock and wouldn't until I'm serious about buying. I had the same problem with trying out a Cannondale.

[indysteel]

In looking at the geometry of the bikes you're looking at and comparing them (in the sizes the shops have had you try) to your Giant Avail, I'm sort of perplexed. The Giant's ETT is 540, which does seem a bit long to me for a 50 cm bike. But the Trek Lexa in both the 54 and 56 have the same or even longer top tubes than that, and the ETT of the Specialized Dolce in a 54 is only a few millimeters shorter than your Avail.

If you're too stretched out on a bike with a 540 ETT, then logic suggests to me that you should try smaller frames than the ones you've tested thus far.
Of course, it bears stating that there's more to fit than just reach. You should also keep a close eye on each bike's seat tube angle, because that may ultimately impact your reach and/or whether you can get your knees where the need to be in relation to your pedals.

If it were me, I'd seek out a shop that knows something about fit and does more than merely eye ball you. I'm not sure what's available in your area, but once you're back in Cincy--if you aren't already--you might consider a visit to Nebo Ridge on the north side of Indy. It truly might be worth your while to work with a decent fitter, and Nebo has one.

[Owlie]

The guy at the Trek shop did say that while I looked more comfortable on the 56, he thought it might be because I'm used to being stretched out.

The seat tube angles on each are different (73.7 and 73.4 for the Treks, 74 for the Dolce and 73.5 for the Giant), and if I remember correctly, I think the stock stem on the Dolce is shorter than the stock stem on my Avail, so that may have something to do with it. If anyone's got a link explaining geometry as it relates to fit, that would be awesome. I'm interested in learning more about frame geometry as a whole, and I think that's a good practical starting point.

As I said, I'm in no position to buy just yet, and they'd probably take a little more care with the fit when I show up and am serious about buying. I'll see what's available in the area with regard to fitters (thanks for the tip, Indy!).

[indysteel]

I can't provide a link to it at the moment because I'm on my Blackberry, but you might look at Peter White's website. He has a discussion on bike fit that might be helpful. Just Google his name and "bike fit."

But looking at your existing bike's geometry is a good place to start to determine what does and doesn't work for you. You mentioned feeling too stretched out on it, but have you ever worked with a fitter to tweak its set up? Even if you're determined to get a new bike, it's far easier to make informed decisions if you work first with what you already own as a frame of reference.

[OakLeaf]

Never been there, but HubBub in the Cleveland area has a rep for doing good fittings.

[Owlie]

I've heard of the shop...doesn't help because I'm moving back to Cincy.

So...It turns out that the Dolce I tried out was a 51 (oops). That would explain why the top tube felt better, but that might be pushing the "small" end, considering that my femurs probably need a 54 or 57.

[Owlie]

But looking at your existing bike's geometry is a good place to start to determine what does and doesn't work for you. You mentioned feeling too stretched out on it, but have you ever worked with a fitter to tweak its set up? Even if you're determined to get a new bike, it's far easier to make informed decisions if you work first with what you already own as a frame of reference.

I've been meaning to. I have about half of it (service costs, anyway) in birthday/Christmas money. The other half...(well, I probably spent it stocking up on yarn to feed my other hobby...)
There's a few things that I know need to be done (cleat adjustment, stem swap, saddle), and one thing I can think of that might need to be done (swap out for bars with shallower drops).

I think you're on to something with the smaller frame size, provided there's enough "travel" in the seatpost to make up for it. Maybe I'll take a little trip over to the shop this week or once I'm officially back in Cincy. I think they have a Ruby in a 54, so I can compare.

[OakLeaf]

I think you're on to something with the smaller frame size, provided there's enough "travel" in the seatpost to make up for it.

Seatpost is almost never an issue. Handlebar height can be with a smaller frame, though - that's why I suggested a fork.