Hybrid carbon nanotubes represent a distinctive platform for nanoresonator-based detection of fundamental phenomena and the development of multifunctional sensors. The resonant mechanical properties of single-walled carbon nanotube bundles are reported. Resonant frequencies ranging from 0.2 to 9 MHz were observed. Quality factors of resonances varied from 77 to 800. An experimental effective bundle Young's modulus of E*=76±4 GPa is extracted. Onset of nonlinear response was observed at large oscillations. Electron beam-induced structural changes were also observed. We discuss these data with respect to reported literature values and structural issues intrinsic to the system.