My wife was checking out bikes at an LBS and the guy there mentioned getting a longer stem for more control as she gets more experienced. (We were looking at a Trek 4500 WSD which has shorter stems for women). Is this bull? Most of what I've seen here says stem length is more about fit and feel than something to adjust as you get better.
Building on that, is stem length measured from the center of the bar to the center of the steering axis? If so, does 75 mm sound right for a Mobius stem on a Hardrock Sport? I'm looking at getting a Thomson (local company, so I'm almost obligated...), but they start at 90 mm. My old bike seems to measure 120 mm, which seems to bend me over too much and put too much pressure on my hands. But my newer bike keeps me a tad more upright than needed. Should I split the difference and go with 100 mm?