Paul, I am not 100% sure myself but I think that a tour bag is the type of design that the pros use, so is very large and really meant for carrying by a caddy. A cart bag is interesting as I think the term comes from the US where a cart bag means a bag that you use when you ride in a buggy. I don't think that it necessarily means that it will be ok on a trolley. At least this is how I interpreted the manufacturers web sites that I browsed. I was going to buy a good looking Burton bag from online golf and couldn't decide if it would fit on a trolley. By the time I had decided it was sold out! So, I went to my favourite range where I have lessons and I bought a Wilson Alpine Cart bag and used it for the first time today. It fit perfectly on a trolley. I am actually glad I didn't buy online as I could poke round the pockets etc. Apparently, most bags are made in the same three factories anyway. I am not sure this helps you much but good luck...