I was about 180 miles away from home at XR650L_Daves house, we had just met and had a good chat for a couple hours, pulled out of his driveway, click to second and nothing , try again, nothing, THANK GOD IT HAPPENED RIGHT THERE!!!!! Pushed it back to Daves garage and this is what Dave found or rather didn't find! From new Dave said it was misaligned and that's why it completely sheared the mating splines off. Daves better at explaining and most likely he will chime in. http://pbisprockets.com/ I bought the bike with it on so was unaware that it was not on correctly. I did a search on PBI here and found a few post concerning quality control problems too, INCLUDING another PBI that Dave happen to have that was also defective. I'm not going to bad mouth the whole company saying not to buy but only expressing to watch out if you do get one of there sprockets. Dave saved my day (actually the WHOLE weekend) BIG TIME by hooking me up with a used 15 tooth stock sprocket Heck of a guy that did it at NO CHARGE! All that I can say is THANK YOU DAVE !!!!