Works for me. I've got a tallbike with 40x17 gear ratio, and a 40 ghost ring. Just barely fits in there without touching the cog or seat stay. Has never fallen out. I should mention that's it's a freewheel setup. I've ridden fixed setups with a ghost ring, and while safe (if done right), the play and the noise can be kind of annoying. Basically it's not the proper way to do things, but it will get you on the road.