Here's the way I understand the relationship between rake and trail. Trail is a measurement between where the centerline of the steerer tube intersects the ground and the center of the tire contact patch( a line drawn straight down from the axle to the ground). The contact patch normally sits behind the steerer centerline. Further behind means more stable. If you draw all of this out with different amounts of rake, you will see that decreasing rake increases stability. Many people get this backwards.