Cyclocross - Funky cyclocross sizing

I get it that cyclocross bikes are going to have higher stand over heights, etc. But I still can't see how this works. I am 6 foot 2 with a 31 in inseem. I don't think that sounds too weird, does it? But if you look at the Giant TCX, that translates to a 53 cm frame.....the smallest one??? What if you are a dude standing 5"7 to 5"10? Am I missing something?

Have you straddled real bikes , or just data?

I think you've got short legs, and yes that probably translates to the smallest frame. I'm 6'2" and have a 35.5" inseam. Yeah, my legs are long, but I also know that 31" isn't average. I can fit on a 60cm frame but typically ride a 57-58 depending on what's available. I'll change the stem if my riding position isn't quite right.

Go sit on a bike and figure out how it feels. You can change stems so easily that if you need to, change it out to a longer stem. A good LBS will recognize this and probably just exchange it.

And set up the saddle backward max.

Do you mean pants inseam, or "cycling inseam"? There is a significant difference.
http://www.rivbike.com/kb_results.asp?ID=39

6'2" and 31" PBH would be very unusual. I'm 6'0" and 35" PBH, which is almost exactly the average PBH for people of my height, based on bikefitting.com's database.

Unless you plan on just straddlewalking your bike around instead of riding it, dont obsess over the stand-over height. Fit the effective top tube length to suit your upper body.

Unless you plan on just straddlewalking your bike around instead of riding it, dont obsess over the stand-over height. Fit the effective top tube length to suit your upper body.

This.

I am 5'9" and have a 34" inseam, everyone is different and you have to find a bike that fits you. i ride a 54.4cm top tube and have to use a few more spacers than is "cool" to get my bike ot fit properly, and i still have a lot of saddle to bar drop.

OP has to put up with an off the peg frame not being quite right,
until ponying up for a made to measure one ..

Try stuff , test ride at the Shop.. change components as needed..

OP, I'm built similar to you but not as extreme being 6' with a 31 inseam. Both my bikes are 54 and fit me quite well. I do not have a whole lot standover clearance but it is enough. You can play with the stem length a bit but expect a pretty snug fit on the standover clearance compared with those with more conventional body types.