You need more than you're thinking. The K9 is RSD, the Chopper is LSD. You will have issues lining up the back wheel with centerline. The biggest problem is that you kinda have to get the parts first, and then make them work. I'd start by calling Daytec or Rolling Thunder depending on what frame you have. The swingarm is the critical component and if need be, you cannot easily modify the existing swingarm. If you can get a K9 swingarm cheap, it can't hurt to just buy it and see if it fits up. Next step would be to change the transmission mount to RSD, whether by cutting off the old one or some type of adapter. Now you have to figure out how to run the belt or chain, since the pillars at the back of the chopper frame are a little different than the K9 frame. Before you do any of this, get a solid width measurement on a K9 wheel, both at the hub and overall tire width, and see if you can make it fit in your existing swingarm. Most likely you'll need a sprotor and chain. Even if the tire is offset a little, it will ride ok. Switching to an open primary will ease your pain a bit as it's easier to offset. They told me I couldn't fit a 180 on my Yamaha but I did, it's just a matter of making the space and getting that tire as close to center as possible. I'll tell you what. I have a chopper frame sitting here and a K9 wheel getting a tire right now. When I get some time this afternoon I'll roll that wheel in there and see how it looks.
