I know this has been discussed before, but the more I read, the more confused I become. I bought a 79 cm400t a couple years ago, put a 120/90/16 on the rear and left a nearly new 3.00 x 18 on the front. It's now time to buy a set of new tires and I find the selection for this bike limited, so I've researched possible sizes, and effect on bike handling. I know most folks say the proper size is the 120/90 for the rear and 100/90 for the front, but my front rim of 1.85 inches is really more suited to a 90/90 or 90/100 which is much closer to the 3.5 inch tire the bike calls for and wider than what I'm running now. How will going to the wider tire affect my handling and why should I go with the 100/90? Also, how is the 120/90 different from the 4.6 x 16 the bike calls for, which is available in a couple tire brands? I know I'd have more choices with the 130/90's, but don't really want to modify the chain guard which is almost rubbing the 120. My current tire brands are Duro up front and Kendra Challenger in the rear and neither seemed to last very long, less than 3000 miles. I ride a lot of curvy mountain roads, but the wear is mostly in the center of the tire, I suppose from accelerating and braking. Probably ran a bit too much air pressure 30-32 front and rear, which I'll lower for the new set to what the manual calls for. I'd like to hear your recommendations on tires that I might use considering the above comments. Thanks in advance for your help. I'm also getting ready to change chain and sprockets and will be going to a 17 tooth front sprocket, if that makes a difference in your recommendations.