we consider tensor products $v_{\\lambda}\\otimes v_{\\mu}$ of irreducible representations of a classical group $g$. in general, such a tensor product decomposes in irreducible components. it is a fundamental question how the components are embedded in the tensor product. of special interest is the so-called cartan component $v_{\\lambda+\\mu}$. it appears exactly once in the decomposition. on the other hand, one can look at decomposable tensors (tensors of the form $v\\otimes w$) in the tensor product. a natural question arising here is the following: are the decomposable tensors in the cartan component given as the closure of the minimal orbit in $v_{\\lambda+\\mu}$? if this is the case we say that the cartan component is small. we give a characterization and a combinatorial description of tensor products with small cartan components. in particular, we show that for general $\\lambda$, $\\mu$, cartan components are small.