Fair point about the range. If it had originally been written as 40-60 @ FTP I wouldn’t have raised my points. Rather my response was on the 60-70min part.
My understanding was that FTP is the maximum average power output over 60min. Ignoring the various ways to estimate it (ramp or 20min), I would imagine that the original posters power curve is not flat between 60 and 70min. Therefore one would assume that his 60min power will always be higher than his 70min power.
Even using a ramp or a 20min test. I would imagine it would suggest that the FTP was wrong if I could be held to 70min.
Please correct me if I am wrong on this.