delay

I know there are probably a lot of tarmac owners out there, and I am hoping for some help. I don't have a specialized dealer nearby and am wondering about sizing. I am 6' with a 32" inseam. I think that I am a size 56, but am not positive. My current bike is a 57 bianchi.

brian416

I'm 5'10" with a 32" inseam, and a 56 is perfect for me on the Tarmac

DaveSSS 

Be sure that the inseam you are quoting is a cycling inseam - floor to firm crotch pressure in bare feet - not a pants inseam. An actual saddle height would be far more informative.

32 inches or 81cm would be pretty short legs for a person who is 6' or 183cm tall. I've got long legs with an 83cm inseam at 169cm in height. My saddle height is 73.5cm.

Noting a 57cm Bianchi isn't real informative either. There are many years and many models with differing geometry.

If you have more info on the year, make and model of the Bianchi, it may be possible to find the geometry chart. Then it's easy to compare the fit to any other frame of interest. Whenever I buy a new frame, I want to know the stem length, angle and spacers needed to make it fit, before I buy it.

delay

The bianchi is an 04 giro. Its top tube is 560mm. I use a 120 stem with -8degree rise. My inseam measured in the manner that you describe is actually closer to 33". I have compared the geometry the best I can with my current bike, and that is how I arrived at the notion that I should fit a 56.

DannoXYZ 

How does the seat-tube angle of the Tarmac compare with your current bike? That will combine with the top-tube length +stem to give you a reach distance. If the seat-tube angles aren't the same, you may end up sliding the seat forward or back compared to what you have now. So that should be accounted for in the top-tube length measurement.

I find it's more important to size a bike based upon top-tube length than seat-tube since you spend more time riding than straddling it.

DaveSSS 

Here's the geometry on your bike and that of the specialized. The reach on the Specialized would be 2-3mm longer than you current frame. Since you have the Bianchi in hand, you can compare the head tube lengths. Then there will be little to guess about with regard to the stem angle and spacer setup.

https://www.bianchiusa.com/04_giro.html

https://www.specialized.com/bc/SBCBkM...=39243&eid=115

Coyote2

Specialized dealers are easy to find. Just go and sit on one.