I have researched this to death and I am just looking for some reassurance. I currently have the S2R 800 (Dark) nonadjustable crappy forks and I have considered the GSXR swap and Superbike forks, but it sounds like the easiest route to take is just get some S4R forks and bolt them right on. Is that right? no shims, no spacers just bolt em up? Any reason why more people aren't doing it this way? Sounds too easy.
I just did this on my S2R800. I used SBK forks from a 2005 749 dark. They are fully adjustable Showa's with the compression, rebound and preload on the top, no need to worry about the bottom adjustment as there isn't anything to adjust at the bottom of the forks. They aren't the best adjustable forks but light years ahead of the non adjustable stockers. Here are the parts and considerations required to make this work:
1. Speedymoto top triple. As the SBK are 53mm and the stock are 50 at the top and 54 at the bottom I elected not to mill out the top triple but replace it and use a shim for the bottom. The quality of the speedymoto stuff is second to none. I was also installing clipons but elected to get the top triple with the holes predrilled for the stock handle bars should I ever want to switch back.
2. Shims for the stock brake calipers. The stock brakes on the S2R800 are ok, not bad, but just ok. If I had the budget I would have replace them. Next on to do list
3. Front fender. The monster fender doesn't fit on the SBK forks.
I had the work done at a shop and couldn't be happier with the results