With jet airplanes being manufactured out of a combination of carbon fibre, titanium and aluminum to withstand the effects of fatigue (exposed to repeat forces at a much higher frequency than bicycles) I would suspect many of the comments above are non-founded. If you are concerned with mixing dissimilar materials one only need to look at how long reinforced concrete (steel & concrete) and timber construction (wood, nails, and steel gusset plates) have been around. However, as with any new combination of materials, there is a learning curve.