So, I live in Northern Wisconsin where the roads change frequently. I switch my tires from studded to soft compound nobby tires regularly, and then one day this happened. I replaced the tube, and that seemed to fix it. I haven't changed this tire since, but it came back. It's in two spots on the rim, and recently now my tire drops to about 7 psi from 40, it's a slowish leak. Almost like a bead leak on a car rim. These are tubed, and I have bought metal spoons off Amazon, which this happened after my second time using them. I can't find any info on the internet about tires sucking in! Only bubbling out. Like I said, it has advanced to the tube not holding air. Any info would be appreciated. These pics are of the tire at roughly 7 psi, it's odd because with the tire fully inflated I also feel a knocking feeling while coasting or peddling, and it goes away when the tire is in this semi flat state
by xMPxR0gue