Basically, if you put that 170 on, your bike would handle like Sh!t, okay, next you have to figure out what do you do with your bike,what tire you like, How you want you bike to act/ handle? 200 if you like that Fat tire look( of course it turn like a truck ) 180 or 190 depending on profile both handle nice & footprint is good on both, dunlops I run 180's, pirrelli run 190's, the slicks I run on the track are 195's, just remember not to mix the brand of tire from front/back. profile might be wrong & put you on your @$$