PS" Another thought here from the above post: Takes about 5 min to cut a groove in a urethane skateboard wheel using the drill and file method, but want to let everybody know the groove is not pretty. But, The shallow concave groove that matched the file shape has performed flawlessly as the chain only contacts the sides a bit only and because its curved the bottom of the chain cannot contact it, yet stays nice and centered as we put it on near a rag joint sprocket mount and they are not the truest and always seem to have a 1/16"- 1/8" wobble. Pedals way easier too for some reason. That stock plastic wheel binds, stops, sags, scrapes. I am fearful of having the chain so tight on cheaper huffy wheels and bearings as to be able to use a spring tensioner that hates bump starting, with the then... slack... bang...snap. I know the front mounted Chain Tensioners are nice, but we had such a bad experience with the last spring tensioner that I am a bit gun shy, plus the 41 half links available to be able to get the chain closer to not needing a tensioner have that cheap little micro cotter key to lock the roller pin and I don't trust installing one. Any tips or experience with those 41 half links would be helpful. Sorry if I hijacked this thread a bit, but thought it fit some of the comments here.