Originally Posted by
chaadster
Well of course, yes, getting what fits you best takes precedence over any number (except, maybe, cost!), and yes, some companies give sizes that aren't a measure of anything on the actual bike, and are rather "it fits like a traditional size 54cm" or whatever.
That said, actual measurements, like the effective top tube length you gave as an example between Breezer and Trek, should be measured the same way, e.g. center-to-center along the horizontal; I can't recall seeing effective top tube measured any other way.
To your point that there are a lot of different numbers flying around out there, yes, you're right about that. I think that once you get those most relevant to you locked in, though, it will be much easier to sift through the options. For example, it sounds like you like longer reach, so bikes with longer TTs are of more interest, but what is the # you're looking for, right? If you can determine its between 23.5" and 24", you can weed out the 23" ETT bikes even though they may be designated Medium or something else seemingly appropriate. Same goes for minimum standover height, though I think your distaste for low top tubes a bit strange.
Or worse, "One size fits most".
Here's what I'm talking about regarding non-standard measurement locations.
Trek's diagram:
"E" is the effective top tube length. As you can see, the measurement is taken at the top of the seat post to the top of the head tube.
Here's the Breezer diagram:
"B", the label being hard to make out here, is their ETTL measurement. They use an arbitrary (?) point on the seat tube and an imaginary point in space below the head tube.
When I measure my current bike using these two basis I get a difference of 1-2", depending on how picky one wants to be about OD or center-of-tube measurements. (Hey, I'm an engineer (albeit software), what can I say?)
But you're right about the standover height; I should actually be thankful for a low one. Getting on and off the bike easily is a priority as I get older. I think any unconscious preference comes from years of riding a road bike with a horizontal bar, from the days before tall seat posts.
Thanks to both you and
cyclezen for your suggestions. I'm going to take another look at the Medium bike before it gets away (it's a killer deal), but I'm not sure it's the one for me. We'll see.
-- Sam