Z1: If you use the genuine front wheel you must use a 17mm axle (check part R-039 or R-158)
If you use a 17/18 inch front wheel use need another speedometer-drive (check part R-017/R-040)
The genuine calipers not fit.
Z900/1000: Genuine caliper/wheel+speedo-drive can be used.Caliper pitch 72mm.
If you mount a 17/18 inch front wheel you must change the speedometer-drive (check parts R-018/R-041)