Short Torso and 5' 3'' QR Dulce or Cervelo P1

I agree that the XS/48 is much better suited for you, but don't have experience with either of your bike choices.  I'm 5'6" with 30" inseam and shortish torso as well and was able to fit a 48cm or 50cm, so I stuck with the lower/lighter one, so I doubt you could truly fit a 51cm well without over-extending your torso/arms or making other adjustments. 

I narrowed my final choices down to the Cervelo P3 Ultegra or a Fuji D6 Comp and ended up getting the D-6 because the pricing was more flexible and the ride less stiff (and the shallow desire to have a "different" bike as you almost never see Fuji's at tri's, which may actually be a bad thing .  I didn't actually get a chance to ride either of my choices but spoke with lots of people with past experiences including members of a university cycling team, and that's the impression they gave me - Cervelo = proven, fast, super stiff but possibly less comfy/forgiving for a new rider. I did get a chance to SIT on both bikes in the shop, but of course that only tells you so much.

Edited by lawrence131 2009-11-08 11:12 PM

This is a VERY difficult question to answer... and the reason why it makes sense to have a bike fit before purchasing....

Gut feeling, says that the QR would work better for you... the top tube is fairly short and tend to fit the female physique better (shorter upper body, longer femurs and greater range of motion). The Dulce is an amazing bike to boot... I used to ride a QR Lucero and my wife is now riding a Lucero... To me, you get a better frame with the QR then the aluminum Cervelo (not that it's anything wrong with al.)

Thanks for the input-- Found some nice deals on Lucero myself and may go that direction.