Just my $0.02; I'm 6'3", 34" inseam, and WAS 290# last year. I went with a large-size 2015 HaiBike FatSix. I absolutely love the thing, but the fully-extended seat-post was JUST long enough to be comfortable; I THINK it's a 380mm. I ended up installing a 400mm dropper, and it's perfect now. It's...