I’ve never experienced it before but think it’s happening to my 21 hardcore. Does it make a noticeable vibration also besides a kinda grinding noise? I just don’t have the experience to know but it didn’t do it going slow but did going faster or with an acceleration. I looked but saw no visible thing that jumped out and track didn’t seem excessively loose but what so I know lol. Just wondering what it sounds and feels like . I’ll obviously re adjust it before I ride again. What tool or techniques can you use to tighten an alpha track with out a scale in the woods?