Here something I realize not everyone will need but that may come extremely handy in case you do. This is an adapter ring (sizes 1-5 mm) to mount narrow (6-9 speed) Shimano® cassette sprockets to 11 speed road freewheel cassettes.
In my case I needed to mount a 7-speed Shimano cassette to an 11-speed cassette mount on my Elite smart trainer. My trainer came with a pre-installed Shimano 105 (or equivalent) 11-speed cassette mount, which was just too wide for the 7-speed cassette sprocket I wanted to mount.
Print with some really strong material at 100% infill. I use a cheap, strong, and easy to print Carbon Fiber PLA, which works great. I have included .STLs from 1-5 mm but you can easily adjust the exact size by scaling on the z-axis. Just slide the ring onto the cassette mount before mounting the sprocket. I have done a few thousand (virtual) miles on my trainer and it works like a charm.
HOPE YOU LIKE THEM, AND IF YOU LIKE THEM, PLEASE LIKE THEM. THANKS!
Enjoy and happy printing!
PS.: Thanks to S. Herring, whose rear wheel hub I used for the rendering.