I ride a 56 cm surly Steamroller and a 54 cm surly long haul trucker where do I want to start on a mtn bike size?? I have my latest project on craigslist (to small for me) and offered to take a vintage mtn bike in trade
Thanks in advance
Roy

How tall are you? What's your inseam or when you buy jeans, what leg length do you get? Without further information, I'd guess you're a medium size frame or a 17"/18".

5"10" 30 " inseam

IMHO, you should be riding a "medium" frame. In a classic frame, this would be a 17" or 18" frame. With sloping top tubes and variations in design, this may vary, just like road bikes but the manufacturer should still call it a "medium". My son is 6' and buys 30" jeans, he rides a 05 Rockhopper that has a 17" frame. At your size, I would not try a large frame. Mountain bikes get thrown around during the ride something that never happens to a road bike, and you have to be able to clear the top tube for the times when you'll fall (it's gonna happen).
Edit: BTW, falling on dirt or into a bush is nothing like falling on asphault. Dirt and natural terrain actually give, concrete and asphault don't.

longer torso, shorter legs. probably have arms proportional to legs.

I agree with Rocco, you probably need a medium size, or something in the 17 - 18.5" range. You can (and absolutely should) tune the reach with various stem and handlebar combinations, but watch your standover on older frames which usually have a straight top tube.

I should clarify what I am wanting this for . I would like a bike that can be put on a trunk rack when we travel , so I can take a bike that is lass temping for a thief than my Surly's . It will see gravel, grass and pavement but not full on mtn bike trails . I was given Chiorda safari folder in a basket completely disassembled. I put it together grease everything that needs grease adjusted etc . Since I am a clyde I don't think it would stand up for me. I put it on the local Craiglist for sale or trade . Basically I will just flip it for the next project. Amazon messed up the prime shipping for the tires/tubes bad enough they refunded my money and gave me the order so I have very little invested
Thanks for the help
Roy

I'm 5' 11",, 32" Inseam and I ride a large full suspension Scott, I think Its a 19.5" frame..

i ride a 20" frame. im 5`11" and a 32 inseam.
going to try an 18" this season....will see if i end up swapping frames