I bought this bike awhile ago the previous owner removed the 6th gear for some reason. First off why would anybody do that? And how easy/expensive would it be to replace? I really want to put a bigger sprocket on the back (still running the stocker) but I dual sport it so riding 55-60mph is a must. However with a larger sprocket and without 6th my top speed will take a hit. Right now its ok at 55 @ 60 starting to strain a little and 65 needs to shift up. Trying to find the best route on this one the stock sprocket blows for trails.Thx.