After 70 miles of mixed rock, dirt, snow riding. I lost 188 studs from the rear tire and 67 from the front. Yes, I know rock rides can be a problem. That still seemed like pretty high attrition! I replaced 174, which was all I had. I then rode another 20 miles, entirely on snow and ice. I lost another 96 studs. That's really poor performance! Snow and ice are what these tires are for! I gave them two stars because when the studs are there, they work decently. However, I will not buy these again!