I tried it with a few different sized spacers as well, the 1mm one was too thin and the gears had some play when I tightened down the cassette. I also tried a 1.5mm one but based on what I read online everything seemed to indicate I needed a 1.85mm one. I'll try the 1.5mm one again. I'll also try something between 1 and 1.5mm assuming I can find anything. I don't recall seeing anything between that when I looked online. Thanks for the help!