I fitted a 120/60 ZR 17 M/C (55W) TL on the front and a 190/50 ZR 17 M/C (73W) TL on the rear. There is a lot of debate on the tyre sizes to use on the forums. I took these sizes from the Pirelli web site for fitment on the Ducati 916.
I have read that the 180 rear profile can be fitted on the 916 and that this gives a sharper response to handling. I cant comment as I have replaced the old 190 with the same size. One reason is that the old tyre was fitted about ten thousand miles ago. Which I think is a pretty good life for sport touring tyres. I have not had any worries with driving in wet or dry conditions and am pleased with the grip level.