Complex sentence: The pulleys had been made by the Smith brothers in 1909 by the Clyno Engineering Company based in Thrapston, Northamptonshire, and in 1910 complete motor cycles were starting to be made using Stevens engines.
Split into simpler sentences: The pulleys had been made by the Smith brothers in 1909 by the Clyno Engineering Company based in Thrapston, Northamptonshire. In 1910 complete motor cycles were starting to be made using Stevens engines.