is the fit the same on the old bike vs the steamroller?
if not then the saddle will not be in the same place, the amount of weight on the saddle vs your hands or feet will change
ideally if you were comfortable on the original bike you need to first set up the saddle on the steam roller to the same height with respect to the bottom bracket, and then ensure the fore/aft of the saddle wrt to the bottom bracket is the same
next you set up the bars to be the same distance from the saddle tip (both horizontal length and vertical drop)
is the fit the same on the old bike vs the steamroller?
if not then the saddle will not be in the same place, the amount of weight on the saddle vs your hands or feet will change
ideally if you were comfortable on the original bike you need to first set up the saddle on the steam roller to the same height with respect to the bottom bracket, and then ensure the fore/aft of the saddle wrt to the bottom bracket is the same
next you set up the bars to be the same distance from the saddle tip (both horizontal length and vertical drop)
hope this helps a little