[yongkun]

I am looking to buy a new frame, currently looking at one particular frame. But with my preference of virtual top tube length of around 54-55cm. I am not really sure which to choose.

Medium: Virtual top tube 53.4cm
M-L: Virtual top tube 55.8cm

Should i go with the medium frameset and go with a setback seatpost or the M-L with a shorter stem?

 

[aengbretson]

How much seat-to-bar drop do you want? If you want more I'd consider going with the smaller frame, if you want less then take the larger one. Obviously the smaller frame will look more "pro" with the longer stem, but I think head tube length is an important factor to consider.

 

[krisdrum]

also make sure the seat tube angle is the same in both sizes.

 

[Peter P.]

Don't buy that particular frame. As much as you like it, it doesn't fit what you seek and you'll always be questioning yourself. Look for something else.

And using a setback post to compensate for the short top tube is wrong. Seat fore/aft is independent of top tube/stem length. Don't use one to compensate for the other.