The spacers need to be shaved a little, and I mean millimeters, and either I need to get bearings to fit the stock swingarm bolt or enlarge the holes in the frame to fit the F2 swinger bolt... Other than that, there is no other modification needed to make it fit in the frame. I didn't measure the two against each other before mounting, just removed the stocker and test the CBR swinger to the frame, only the spacer in the swingarm was causing clearance issues. However, unless you run it monoshock, then you'll need appropriate bracing and mounts, if you keep the stock dual shocks, you'll need to weld lower mounts on the swingarm itself. I'm still in the air and discussing with a few members of my usage of the bike and pros/cons of both setups, I'm leaning more towards Monoshock right now and it's cleanliness and centralized weight.