S&S Cycle 07-17 BT 585C Chain Drive Camshaft KitThe 585 cam is designed for 88 to 95 inch engines with compression ratios from 10 to 10. 5: 1 and 100 and 107 inch engines at 9. 7: 1 to 10. 5: 1 compression. Many riders are leery of the stock chain cam drive in late model big twins. mt is true that the early version introduced in 1999 was often not well suited to high performance applications, the later version introduced in the 2006 Harley Davidson Dyna model, and later incorporated in all big