Originally Posted by
DaveSSS
The flaw in this analysis is the stem reach changes when the angle is changed. Most stems are measured along a line through the center of the steering tube clamp and the center of the handlebar clamp. A 100mm stem in the -17 position should be 100mm long, but when flipped up, the horizontal length becomes 829mm. There are other stem calculators that show the change in reach and height, when a stem is flipped.
That said, most people just change one thing at a time. Change the bars, but leave the stem alone, since any change in reach is very small.
Except, if I'm reading the OP's graphic, what you're talking about is mentioned in the calculator graphic he posted (2mm less reach and 4mm lower stack) and he's already aware of this.
I do agree though that a change in bar width (assuming the bar itself's reach is identical between the wider and narrower bars) isn't worth worrying about. In fact, OP may have it backwards, IF the wider bar he's installing more closely matches his shoulder width, then the distance would be shortened from shoulder to bar, not made greater.
I'm curious what length stem he has at the moment (guessing an 80mm)?