I have a new Giant Defy 1, and have had trouble finding a comfortable saddle, finally settling on a Selle Royal Ellipse Athletic, because of the long, deep channel it has, which relieves pressure on my perineum. Even still, there was some pressure, so I changed the stem from a 110mm 8° to a 90mm 25°, which brought the handlebar up a fraction and back a little over an inch. This results in a slightly more upright riding position.

The more upright position is more comfortable, but on a fast downhill run today, when moving off the drops and back to the hoods, the front end seemed a bit more squirrelly. I cannot imagine the bike coming out from under me at 35 MPH! And I noticed that, when I look down, I can see the front axle just barely ahead of the handlebar. Is it just me, or could the stem change have made my bike unstable enough to be unsafe?