Metzlers have the new alpha-numeric sizes for stock replacement. \\; Outside of that your on your own if you are trying to go a bit wider without a wide tire kit. \\; I have heard of some running a 150/90-16 but you give up some load capacity. \\; Just watch your tire pressures. \\; Metz's are finicky when it comes to air pressure.
I run the 150's and love them. Tire size has nothing to do with them "coming apart" Metzler makes a great tire and you will have no problems with the 150s on your bagger!
A 150 \\;metz will fit fine. \\; A 160 might need a little shaving of the lower belt guard. \\; There is something about the Metz tire that just looks better than the dunlops. \\;