Hello..I am in the process of buildind a new bike..more in the preliminars..I now ride an old mountain bike with a rigid fork and road tires for commuting and even did a five days 400 km tour last summer,That old orbea measures about 21 inches(51cm +/-) seat tube and a tad under 22.5 or so top tube.I have 26" wheels on it and the top tube is just under my croach,not touching near the seat,and getting close in the front of the bike.It has a flat handlebar with end bars.I want a steel frame with a 1x11 transmition ,700 and perhaps drop bars,not sure..sort of a gravel idea..I was looking for a hand made steel frame probably size M or 52 and had the funds,but other projects were in the way and now im on a budget .Looking around i found a Ritchey Swiss cross frame,second hand for a good price,and being a Ritchey fan and having sold my old Ascent and missing it ,i naturally fell in love.The Swiss cross cantilever might not be the best frame for my touring do it all project,but its gorgeous..I mean its a CX frame..it is also an XS size..51cm top tube,and 48 cm seat tube (center to center).i am 172cm..5'9 ..a bit on the short size..not long legs either .but the SX frame seems quite tiny amd even Ritchey bikes told me its too small for a guy my size ..What do you think..I want the frame based mostly in looks !!!

It's too small.

And it is going to handle weird if you load it with paniers.

22.5 X 2.54 = ~57cm top tube.. Dropping to a top tube of 51 cm is not a small change. Agree with [MENTION=225388]Kontact[/MENTION], too small.

Mountain bikes are generally made with longer front centers, to be used with short stems, for maneuverability and stability on steep downhills. At 5'9", your road bike size would be 52-55 cm, with a 53-55-ish top tube. If carrying loads, aim for the upper end of this range for stability.

Do you know what fit you want on the bike? If you do, then it should be easy to draw out what you wish to do. If you don't know what sort of fit you like, you might wind up with something that fits you, but you don't like the fit it gives.

That's sort of many peoples downfall when the get a bike. They buy bikes that aren't made to give them the fit they want even though the bike can provide them a proper fit for their size.