Shipping config based on "Give user group" promotion

I am using cs-cart 2.1.1

I have an Item that call for a special box (not oversized). With some order they may order a few other products that fit with this box, in this case everthing works normally. Were my problem is is when they or alot of extra products. and the order has to go into multiple boxes.

So what I was trying was this. Setup a a hidden user group call “ship-1”, then created a shipping method that uses ups-ground and and addition charges based on weight ( I know a good working weight for the special box of with product. I set this ship method to only the user group “ship-1”. Next great a hidden promotion so when a customer buy the item and the weight exceeds the single box weight, it would give as bonus Give user group: set to “ship-1”.

I thought bonus of Give user group would allow a different shipping method to show.

Any thought on were I am going wrong?


When customer buys product “A” without any other product or with less than “x” amount of total package weight – use normal ship methods.

When customer buys product “A” with any other products and total package weight is more than “x” – use alternat ship method.

Maybe that will clarify what I'm trying to acomplish.