Hey all. I'm seeking opinions regarding frames that use a mix of carbon and alloy parts. I recently built up a Fuji Roubaix frame for my son. It's a mix of aluminum and carbon seat stays. I recently saw a video with an English carbon frame expert who advised that it's a bad idea to attach carbon components to metal components in a frame. The reason is that the metal will expand or contract with temperatures, but the carbon will not. This, he argued, stresses the areas where the carbon and the metal are joined, and that they eventually will separate at those areas. I see the carbon/metal combination with a lot of forks. I run such a fork on a bike, where the steerer tube is aluminum, but the lowers are full carbon. I imagine lots of us have forks of such construction. This worried me, as I live in the desert where we get extremely high temperatures. I was also thinking about buying a new frame made of high-end steel, but with carbon seat and chain stays. Now I'm wondering if that's such a good idea. I'm also worried about my son's bike falling apart! Does anyone have any perspective on this issue? Thanks!