I just came across this website while searching for an answer to an anticipated problem. I don't know if any of you can use one, but there is another option here. While they are a little pricey, what isn't, they do allow a lot of horizontal movement also. The product is Kayula Toughbar, comes in different lengths to 27.5", and extends your existing RAM B size system. Take a look at it, and see what you think. I am thinking if the bar is mostly vertical it would work (HB 788ci), but if the bar was in a more horizontal position a guy might have problems in rougher water or when running. I like the concept though.