Bikes for big people

I suppose it's safe to says that they have little experience with really tall customer, rather them to be honest than try and make one.

The problem with huge frame is that a normal triangle frame will be a lots more flexible due to the geometry (not just tubing), essentially from what I gather, a tall head tube mean the frame won't have a normal triangle, just a bizarre square and a rear triangle.

a sloped TT frame would be a good idea for someone like your father hobo, assuming Mercian couldn't do a horizontal TT one without compromising strength (and not just tubing).

So you're suggesting a touring LoPro?