This might be a common question but I couldn't get anything related to pop up under search.
I currently ride a 56cm road bike but am thinking of getting a Surly Big Dummy for enlightenment . However I'm not sure how the frame size translates, and I won't likely be able to actually find a Dummy to try out before ordering. Do they go by mountain bike fit? I'm also concerned about finding a correct fit because of the curved top tube. If it helps I'm about 5'11 with a 32" inseam/max stand over.
Any suggestions/links appreciated.
The Big Dummy does not have standard mountain bike geometry. The top tube is longer than typical.
Sizing is highly dependent on what handlebars you're going to run. If you're running a flat bar, I would go down a size from your normal MTB size. If you're running swept-back bars, it should probably stay the same.
Doesn't really answer your question, I know. You're looking at a M or a L, and could probably get either to work without issue.