This study presents articulatory data on the durational and timing characteristics of Russian onset clusters and their change as a function of speaking rate. While there is increasing evidence that languages differ systematically in their consonant-to-consonant timing, little is known on whether this difference also entails different implementations of speaking rate changes. Russian contrasts with languages like English or German in that it has little overlap between onset consonants. Relatedly, stop consonants are obligatorily released. We investigate whether these global timing characteristics have implications for the implementation of speech rate changes. We hypothesize that Russian onset timing may vary little as a function of speaking rate, with rate affecting consonant duration rather than C1-C2 timing. Also a cluster's sonority profile (e.g. /bl-/; /lb-/) may factor into the implementation of speech rate changes. Results show, contrary to expectation, that both duration and timing of the consonants in a cluster are subject to change. However, there was a less of a rate effect for clusters with falling sonority, pointing towards their lesser flexibility in timing. Our results also reveal significant differences in the durational control of C1 and C2, challenging current models of durational organization of consonant clusters.