This first thread has been in the works for a while. The "pros" involved in this project are 202dy, walterw, JLS and myself (Turnaround). I approached the others a while ago after hearing once again that shimming a neck can cause a ski jump. I've heard lots of opinions from many sources about the cause of ski jumps, but no actual facts concerning the subject - opinions are not facts in my book. I decided to enlist a few of my TB friends to join me on a study of ski jumps to uncover the facts about this relatively common occurrence. The result of this effort will show up in this thread. First, a stab at defining what a ski jump is. It is an apparent rise in the fingerboard and/or neck occurring near the body joint of the instrument and continuing to the bridge end of the neck. This is not to be confused with relief which is a gradual, slight, and relatively even curve along the full length of the board. The ski jump is a much more pronounced curve occurring for a short distance at the butt end of the board. Sometimes this distinction gets lost - I have heard excessive relief called a ski jump - it isn't, it's just excessive relief. First off, the pro team is going to be examining instruments that exhibit this condition. We are going to MEASURE what is going on. We aren't just going to sight the curves in the neck, we are going to put some tools to work and determine (in thousandths of an inch) just what amount of curvature is occurring, and just as importantly where it is occurring. Important to the study is where that curvature begins to deviate from the normal relief curvature of the neck. Once we have a body of measurements we will be able to start to look for the causes of this deviation. My thanks to 202dy, walterw and JLS for agreeing to participate in this study. And my thanks to Joshua and Heavy Duty for agreeing to champion this effort and to enlist the support of the TalkBass team.