Let $\overset{\sim}{K}(X)$ and $\overset{\sim}{KO}$ denote the reduced stable isomorphic classes of complex and real bundles over X and $\rho$ be the realization map. We know that $\overset{\sim}{K}(\mathbb{S}^2)\to\overset{\sim}{KO}(\mathbb{S}^2)$ is a map $\mathbb{Z}\to \mathbb{Z}_2$ is non-zero map as the realization of the Hopf bundle will be non-zero. Is $\overset{\sim}{K}(\mathbb{S}^{8t+2})\to\overset{\sim}{KO}(\mathbb{S}^{8t+2})$ (which is also $\mathbb{Z}\to\mathbb{Z}_2$) non-zero map for any $t\geq 0$? If it's true, please give one refernce.