New Moto Guzzi Door Mats Available Now
Nope , the 80 series tire will cause the Calvin to explode , shredding into a brazillion little pieces . Or it won't cause any problems . Likely the latter Dusty
The 140/80-17 rear tire is going to make your gearing a little taller (250 rpm) and make your speedo more accurate, while raising your seat 1/4" and your bike will lean over a little more on it's side stand, + give you a little more ground clearance when cornering. Your rear tire should last a little longer too. The taller tire should fit OK but you will lose a little clearance between the tire and the rear fender which shouldn't matter unless you ride 2up + a lot of luggage and then it might matter but not automatically, unless you have put softer rear shocks on the bike too.