Anyone reading this thread needs to keep in mind that there is a noticeable difference depending on exactly what you are starting out with when changing front sprockets. Stock Americas are 17/42 (2.47:1), 790 Speedys are 16/42 (2.63:1), and 865 Speedys are 16/43 (2.69:1). I changed my TA to 18/42 (2.33:1). If I decide that it is a bit high now, I'll change the rear sprocket to 18/43 (2.39:1) which is about half way between stock and where I am now. This probably should be stock for this bike. The new 865 T100s and Thruxtons come with this combo. Also, the 790 T100 and Bonnies that have changed their stock (17/43) to an 18T front now have this combo. I have yet to hear from one of those that have changed that didn't think it was the best compromise. Many America owners may get the wrong idea in that "43" bikes changing to an 18T still have a lower final drive than Americas with 18T.
