Ok, I'm probably posting this in the wrong spot, but at least I'm getting it out there...
But,
I did put the large Plastic box on the back on my bike.
It will releive my back of carrying back-pack weight, but now the bike has
a definite wobble at low speeds, and clunks when I go over bumps...
Even these two are worth the trade off against getting a bad back.
Question is, how to stabilise an unstable object ?
I'm going to start a new post for that...