gearhead1331 wrote on 11/08/08 at 15:40:10:What is the biggest tire size you can use with the stock rim? I have found a bad ass rear tire but the size is 170/80 R15.
Looking at Dunlop's site, at the K555/K555J BW rear tires:
http://www.dunlopmotorcycle.com/tirecatalog_category.asp?id=8#tire41 Tire: + Rec.Rim = Diameter x Width
140/80B15 + 3.00 = 24.17 x 5.87
170/80-15 + 3.50 = 25.98 x 6.50
Our rim is only 2.75" wide, less than the recomended for the 140, far less than recomended for the 170. The skinny rim, if you manage to get the tire on, will pinch in the bead and cause it to be slightly taller than the given spec.
Compared with stock the 170 would need almost an inch more space radial and about 3/8" more each side. The 170/80-15 WWW is 6.9" wide, would need over a half inch more each side.
Looking at my bike there just might be enough room. very tight behind the right passenger peg, and you would have only a quarter inch or so clearance at the front of the swing arm.
What you can do and what you should do is often different. According to the tire manufacturers, who should know what is acceptable, even the 140/80 is either maximum or too wide for our rim.