spur=worm ? i dont know. but my ramsey saved my butt one time. i was dropping trees on my property (120ft cedar) and i had my ramsey tied to it and winching it while my buddy cut and drove wedges and it started to fall the wrong way and with out the winch it would have fell threw power lines and the nieghbors cabin. and the truck was anchored to a pretty good sized tree in the rear and the cedar actually started pulling the truck and the tree down hill, the tree i was anchored to pulled over and down pinching my truck between it and the ground putting a nice U shape in my tailgate, but i pulled the cedar down. ever sence i have loved ramsey worm gear winches. again just my opinion