I have been interested in doing the same to mine. I have seen shorter springs that can lower the whole back end on a few in town where i live. One of the guys who has done this says that he got them off a Harley Davidson sportster. I have also seen one where the guy actually took two rods and pretty much made his bike into a hard tail. It looked good but the ride was much rougher. So there are a few ways to get around it. If you do I would be interested in hearing how you went about it. maybe you can even post some pics.