Yes, I ended up finding some more info on XS11.com All 650s through 1100s had the 19" front with a 17mm axle. The 400s had a 18" front with a 15mm axle. So I would need a 1mm spacer or it looks like there may be a bearing that was used on some Suzukis that has the same outer diameter as my XS11 forks, but has a 15mm inner diameter. I haven't tracked down that part number yet, but I will post it if I find it.