Originally Posted by
mconlonx
Good luck with that... Most bikes have tt at least equal to st, most are longer. Probably look for bikes with a 54 st measurement, they'll be most likely to have the tt measurement you need.
Agreed.
Also, the seat post allows adjustment, so actual seat tube length matters little, IMHO. Personally, I don't think you will be able to comfortably stand over most 56cm bikes, without a sloping top tube. As others have said, sizing is very personal, but I would think you to be almost a perfect fit for a 54cm road bike, perhaps a size smaller if it is a cyclocross bike with a tall bottom bracket.