  Generalizing the quantum sine-Gordon and sausage models, we construct exact
S-matrices for higher spin representations with quantum U_q(su(2)) symmetry,
which satisfy unitarity, crossing-symmetry, and the Yang-Baxter equations with
minimality assumption, i.e. without any unnecessary CDD factor. The deformation
parameter q is related to a coupling constant. Based on these S-matrices, we
derive the thermodynamic Bethe ansatz equations for q a root of unity in terms
of a universal kernel where the nodes are connected by graphs of non-Dynkin
type. We solve these equations numerically to find out Hagedorn-like
singularities in the free energies at some critical scales and find a
universality in the critical exponents, all near 0.5 for different values of
the spin and the coupling constant.
