Note that when he says 5.67ft he doesn't mean 5ft 6 inches, he means 5ft 8 inches (as in 5ft and 2/3rds of the way to 6ft), so if you're 5'6" like @bazschmaz and you also ride a 50cm that would make sense.
Or maybe you're actually 5'8" as well and are just more comfortable on a 50, just thought I'd put it out there because it confused me at first.
Note that when he says 5.67ft he doesn't mean 5ft 6 inches, he means 5ft 8 inches (as in 5ft and 2/3rds of the way to 6ft), so if you're 5'6" like @bazschmaz and you also ride a 50cm that would make sense.
Or maybe you're actually 5'8" as well and are just more comfortable on a 50, just thought I'd put it out there because it confused me at first.