Lots of guys look in here. How about one of you guys explain the mechanism and action of lock ups and sliders please.
Jerry, per your request above, find below a few pictures of lockup clutches. The first one is a 2 stage lockup similar to Bills. The next two pictures are of a multi stage lockup similar to the one in my no bar KZ I race in the Crazy 8's class. If you look carefully you will note a few differences in the styles of lockups. The main thing to note is the similarity. Both bolt to the existing pressure plate of the bike. There are 5 arms that pivot on the lockup. They swing out as engine rpms increase to apply more inward force to the stock pressure plate, thereby squeezing against the clutch plates to keep it from slipping under high rpms. By adding weights(nut, bolt and washers) to the arms, the lockup applies more inward force to the pressure plate but this happens at a lower rpm which causes the clutch not to slip as much off the line. The lockup effective begins exerting extra force after the static springs have maxed out pressure against the plates.
Now that second and third picture is of a multistage clutch. It works a little different because it has little springs inside that lockup hat to keep those arms from swinging out freely and applying force to the pressure plate. The tuning kit comes with 4-5 different rate springs so you can tune the clutch as to how quick that final stage kicks in. So, you are in reality sliding the clutch without holding the lever. When set up right, you can almost throw the lever out immediately and let the multistage do the work for you. A multi stage takes a while to set up and you might go through several clutch packs until you get it right. Once set it, you typically don't have to adjust it anymore. I use one because I'm spraying nitrous and don't want the clutch to lockup fully until right after the spray starts about 2 seconds off the line. It would be difficult for me to run 8.60's @158 mph on a stock hand clutch on that no bar bike.
I hope my brief overview helps to get a basic understanding on how these clutches work. I'm not an expert and likely left something out but when running a no bar bike, you cannot allow a lockup clutch to come in too soon or its cause serious wheelie issues. In this case, soft static springs are a must and use very little weight on the arms. Engine rpm will handle the rest down track as the arms swing out more to apply pressure.
