I'm glad you said`that you know of',Paul,`cause I don't pretend to know `em all and their sizes.But of the new ones,the Autopower and other Avantis are the biggest to my knowledge.Now,in the used dept.,the old Motobecane was really a big,tough bike.But at 6'3" I'd definitely be looking at the Autopower or if you wanna take a chance on the Stinger or Supersport(unexplained tranny problems that could just be isolated cases),they're big too.The Tomos' I own and have seen are just barely big enough for me(230lbs.and a little over 6'),and they're not as supple feeling as my old Sebrings.Sitting on a Tomos I feel lower to the ground.Just find a dealer close by and test-ride one of each if they'll let you.I forgot where you live?