Looking for information on a small plastic spacer ring that sits inside the axel bore of my Tomos front and rear wheel. I removed the bearings and the distance bushings to find this piece and it’s not noted on any parts diagram for Tomos wheels. It’s a black plastic ring and has a number on it, 28x19.5x5. Does anybody know what this part is called and is there a replacement? These are cracked and probably should be replaced. Could this be a hub centric ring of some sort?