I'm 6'6" and I've found that I can't get comfortable on anything smaller than about a 65cm frame and my favorite bike is my plain jane old Raleigh Super Grand Prix.
I also have knee troubles so I'm very sensitive to sizing when it comes tro bikes due to knee pain.
Hi ten steel and a bit heavy but super comfortable, cheap and say what you want about modern bikes but I typically have no trouble keeping up with or riding faster than people on modern lightweight stuff.
It's not all about the bike, it's got more to do with the rider than anything.
This is my commuter and long distance bike. It's a 68cm.
This is my backup which still need some sorting to get it comfortable because as it sits it hurts my knees, it's a 65cm.
