I was wondering if I fit a 57cm (center to top) frame.
I am 5'10" with about 33 inch inseam.

"Disclaimer: you should go to dealer and have them fit you."

Now, with that out of the way, I am 5'11" with a 33 inseam. I ride a 57cm C50 and could have gone to a 56. Right now I think the main issue is how many spacers you'll need to run. I'm using 1.5cm of spacers with a 130mm stem and a shorter reach bar. I also have about 5cm of saddle to bar drop.

If you run with more drop, the 56 seems to be the better bet.

Here are a few data points FWIW:

- I'm 5' 10.5" and ride with a saddle height of about 74 cm + change. Compared to the average guy, my arms are a bit longer than normal.

- I currently ride a 56 cm Dream with one spacer under the stem, and a 12 cm Deda Magic stem (82 degrees). I'm considering changing to a 13 cm stem (I'm not riding with my back flat enough).

- Based on my measurements, the Competitive Cyclist fit system recommended a 57 cm frame (I bought the 56 cm because it was on a close-out).

- I've also been professionally measured for a custom frame (Cyfac - I didn't buy it). Based on the recommendations of the Cyfac system (in which the top tube length is very important), I'd need to get a 57 cm Colnago frame to get about the same top tube length.

- I've just ordered a C50 from Mike Perry. He goes solely by saddle height. He was unequivocal that I should ride a 56 cm. I took his recommendation on the size since I'm pretty happy with the fit of my 56 cm Dream. I'll probably use a 13 cm stem on this one.

Bottom line, if you're going to drop serious coin on one of these bikes, get measured first, but realize that the resulting frame size recommendation will be based on the judgments, theories and experience of the person making the recommendation. And at the end of the day, you'll still need to fiddle with the components (stem, saddle height and set back, etc.).

Best of luck.

Removed

I was wondering if I fit a 57cm (center to top) frame.
I am 5'10" with about 33 inch inseam.

Try this: Wrench Science Sizing System (http://www.wrenchscience.com/WS1/Secure/Fitting/Height.asp)

Try this: Wrench Science Sizing System (http://www.wrenchscience.com/WS1/Secure/Fitting/Height.asp)

Wrench Science is good. You can also try this one. There is a good summary explanation in the fit section of the Colorado Cyclist website as well.

http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO

I was wondering if I fit a 57cm (center to top) frame.
I am 5'10" with about 33 inch inseam.
I'm 6 foot. The two Colnagos I ride most (!) are both 57cms. My C50 feels a bit bigger than the MXL although both are comfortable ++ and have the same measurements/geometry. I would suggest tweaking the bits (of the bike) to get everything in focus. It is surprising how tiny adjustments can make a huge difference (when the basic size is OK).