In 2009, the Large Hadron Collider (LHC), the world’s most powerful accelerator became operational, producing mainly proton-proton collisions at multi-TeV center-of-mass energies. This allows experiments, such as the Compact Muon Solenoid (CMS), to explore the so-far uncharted physics at this energy scale. One of the, in the meantime world-famous results of the first LHC physics run that recently ended, is the discovery a new particle with properties resembling those of the long-sought Brout-Englert-Higgs boson. An additional goal of the LHC is to search for new physics phenomena and particles that cannot be described by the well-known Standard Model in particle physics. To this end, to extend the LHC physics reach more and more, several shutdown periods are foreseen to gradually increase the luminosity of the accelerator. The 1st Long Shutdown has just begun and will bring the LHC to its design luminosity and energy; a 2nd shutdown scheduled for 2018 will double the luminosity and a 3rd around 2022 should bring the machine to the High Luminosity phase with ten times its present design luminosity. To keep up with these luminosity increases, also the experiments need to be upgraded. CMS is planning several upgrades, among others to its Muon System and Silicon Strip Tracker, in which the CMS groups from the UA, UGent and VUB are involved. Here, dedicated R&D is proposed, in preparation of the upgrades of these two subsystems during the 2nd and 3rd LHC Long Shutdown periods.