umm I see that Ray, I seems that you could be right, but my question is that are they mainly for the calvert leafs like they show? I do see that the calvert leaf isnt a laminated leaf spring(multi) theirs is more of a simple suported leaf without any reinforcment of the front eyelet, were its a little easier to read the elasticity of the material and control the rebound of that single leaf with the trac bar, on a laminated leaf I guess you have to weigh the options of use and style of leaf from semi-elliptic to full taper or parabolic spring and also the location of the spring clamps that are used to help with stress distribution from impacts and there impact on leaf wrap, I will keep looking at the options for cal-tracs but the varibles of use on a leaf other than a controled cal-tracs single leaf, to me is a lot of more hassle and stress to add a second binding device on a multi leaf that is already designed to equalize impacts, then again I could be WAY off, Im no expert just a regular old racer LOL thanks for making me use my noggin Ray, now my head hurts