I wanted to share a recent change that was made on my Calfee Tetra Tetra to improve its shifting. The 10 sp. IRD cassette has been problematic, and several mechanics have said that the Shimano rear cassette would shift more cleanly than the IRD. After numerous attempts to get the IRD to shift more cleanly, my LBS mechanic decided on a fix: use 8 cogs from a Shimano cassette and attach the 28 and 34 cogs of the IRD for the big hills. Since this was done I have experienced smoother shifting and less skating.