  We present a theoretical study of a mixture of antidipolar and nondipolar
Bose-Einstein condensates confined to an infinite tube. We predict the presence
of a spin roton and its associated instability, which triggers a continuous
unmodulated--to--supersolid phase transition. We characterize the phase diagram
of the binary system, ranging from the quasi-1D to the radial Thomas-Fermi
(elongated 3D) regimes. We also present the dynamic formation of supersolids
following a quench from the uniform miscible phase, which maintains phase
coherence across the system.
