Originally Posted by
Tourist in MSN
When I put my bag onto the bike, I immediately notice the change in handling, and at slower speeds I notice the front wanting to flop over to one side when I make a tight slow turn. I want my bag center of gravity to be as close to my steerer tube (steering axis) as possible so the handling is impaired less.
Adding dunnage to the front of a bike accentuates wheel flop and speeds up handling. ("Wheel flop" is a real term. It comes from rake&trail and is caused by the bike kneeling as the bars are turned.) If the weight of the dunnage is attached to the bars/stem/steerer/forks*, it increases the moment of inertia about the steering axis and slows handling, counteracting the wheel flop to some degree.
*Cargo bikes, some folders and Moultons attached front dunnage to the frame and do not benefit from any increase in moment of inertia about the steering axis.