How to fix parts of object I don't want subsurfed?

I’m making a wheel, and the wheel itself has five main supports connecting the rim to the axis. I’ve modeled one of the supports, then duplicated it and arranged it to make a wheel. The problem is that when I apply subsurf modifier, it destroys what were previously seamless connections between the parts

I’m not sure how I can fix this problem without making my wheel look inconsistent. Beveling the joints flattens the part out too much, which ruins the look of the streamlined wheel.

Should I join them all in one object, then apply subsurf?

Im not sure but do you have multiple modifiers on the model? cause it could be that they are in the wrong order. try moving your subdiv modifier up or down. Another way is to conect the 2 models and then put a subdiv on it.

It’s all cool, I fixed it. Just joined all sections together, Merged vertices at edges then applied a subsurf!!