Just picked up a pair of baskets at a Garage sale for 50 cents. I would like to be able to attach them to my rack in a way that is secure and stable but that can be easily removed for when I am not commuting. Any suggestions?

Plastic zip-ties would hold them, but I'm not sure of how securely when loaded.

You'd have to cut them with diagonal pliers to remove them, which would be easy.

I have fiberglass boxes on my Giant rack, but I secured them by drilling seven holes in each and tie-wireing them on with 14 gauge galvanized wire.
I can't get them off now, and it looks like barbed wire.

Photo:

The left box is kind of lifted up by the pull of all those bungee cords.
The right box has a five pound lead acid battery and stays down.

do you think velcro straps would work?

get some p-clips! that should work.

The metal hooks that Jandd uses for their panniers are available seperatly. 1. Attatch to upper edge of baskets. 2. use mini-bungee cords to go from bottom of rack to basket bottom, keeping the basket hooks pulled down onto the rack.

Or, you could use nylon strap and buckles or something else to go from one basket to the other across the top of your rack. In effect you make the two baskets into one saddle bag unit. Use mini-bungees at the bottom as above.