</font><font color="blue" class="small">( Does anyone know where I could pick up such a beast? size and bore are not important. Thanks )</font> i have a ballantine trencher chain catalog im looking at now it does not show 2.125 sprocket or chain shows 2.043 2.609 2.648, you can get this catalog at 1 800 328-2424 or www.ballantineinc.com by the way what trencher do you have