Originally Posted by
slcbob
Not in my experience or in theory -- the weight up high on your back (backpack, messenger bag) is LESS stable, due to higher COG and less rigid attachment.
Concur bunny hopping is much harder with panniers. Bunny hopping moves the bike relative to the rider, and the more weight directly attached to the bike rather than "sprung" through your body, the harder it is.
I won't bother to type it out....
A bike is also an example of an inverted pendulum. Just as a broomstick is easier to balance than a pencil, a tall bike (with a high center of mass) can be easier to balance when ridden than a low one because its lean rate will be slower.[16] However, a rider can have the opposite impression of a bike when it is stationary. A top-heavy bike can require more effort to keep upright, when stopped in traffic for example, than a bike which is just as tall but with a lower center of mass. This is an example of a vertical second-class lever. A small force at the end of the lever, the seat or handlebars at the top of the bike, more easily moves a large mass if the mass is closer to the fulcrum, where the tires touch the ground. This is why touring cyclists are advised to carry loads low on a bike, and panniers hang down on either side of front and rear racks.[17]
So unless you have a lot of weight to carry, you're better off having it higher up... it takes more to lever(aka balance) but you're more stable over-all... which is the ideal solution for blasting through snow banks and slop(provided you're strong enough to manipulate the balance)... try standing up just as you go over a snow-bank instead of sitting down - you'll notice a difference!