Yeah 120 is IMO too large for the stock wheel. My front wheel is 1" larger than stock and I run a 120 on IT. Front tires need not have the extra bulge IMO.
Oh and I don't believe a 140 would fit between the forks.
I am really enjoying it. It corners really really well and it has a small "crown" to it that is stable when going straight but allows you to lean instantly to the sides without affecting low speed steering. Plus I didnt have to lower the fender at all, still looks stock!!!
Also the added extra air volume is nice as well, takes the edge off the road vibes and small bumps like parking lots and sidewalk edges.
Had them for almost a year now and wear pattern is good, plus they look bad *** on the bike. Have gotten more than compliment on the tires alone.
I have the 180/55ZR18 on the rear and it is performing just as well as the front. Oh and did I mention they look really good :biglaugh::biglaugh: