I see a lot of talk on here about "I have long legs and short torso" or "I have short legs and a long torso." How does one know this? I know my inseam and my torso, but is there some ratio that says your long or short in leg? And how does this generally affect bike fitting?

I'm 6'1.5" with a 88.5cm inseam and 61.5cm torso (measure to sternal notch).

I'm looking at entry level tri-bikes - notably the Cervelo Dual and Guru Cron'Alu. According to Zinn's "Complete Guide" (which does have some instructions for tri fitting) I need a frame a seat tube in the range of 56.5 - 61cm and a top-tube length of about 58cm for a steeper angled bike (read "tri-bike").

So, I'm looking at the Dual in "58", it's top-tube is 589 in 75 degree configuration and the Cron'Alu in "59", it's top-tube is 580 in 76 degree configuration. The Dual sounds a little long in top-tube, but I'm just not sure.

Now I'm expecting people to say "go see a bike fitter." The problem is that I have a hard time believing that any bike seller isn't ultimately motivated to "fit" you to a bike that they happen to sell. Now if you can go to BikeSport in MI that apparently sells everything, that's not a problem. But here in SoCal, no one sells everything. TriZombies sells Guru but not Cervelo, Helen's sells Cervelo but I don't trust them and their pushy sales tactics at all.

This sucks.