On 06/08/2020 10:23, Simon Mason wrote:
On Wednesday, August 5, 2020 at 11:08:06 PM UTC+1, TMS320 wrote:

People also fall over when they can't compensate for a slippery
surface or a step. But if you're carrying a bag on your back, make
sure the straps are done up properly.

That's the key. If the straps are tight to your chest, the load will
not shift.

I once rode with one of my children's school bags that only had one
diagonal shoulder strap. That was irritating because it kept trying to
slide round my body. When walking I use a bag with a chest strap to pull
the two shoulder straps together to reduce gait induced swing.

The only problem with heavy loads on a bike is that the weight makes
handling and the process of getting on the bike awkward. When it's
working as a bike, the forces make the loads stay in the plane of the
bike (like an aeroplane, not a car). Nothing shifts.