140 has a rating of 76V (882 lbs @ 149 mph) 120 has a rating of 68H (694 lbs @ 130 mph) I have a 21" front wheel that is 3.5" wide Hogpro on a 2008 Ultra Differences: 0.66" taller sidewall 0.79" wider treadwidth 1.11" taller (may need to raise fender) 702 revs per mile vs 730. Not significant since its on the front. Rear would change gear ratio. I am thinking this tire will be more stable since its a little wider. Just a wee bit taller as well. Any thoughts? I'm gonna try it anyway and let you guys know in a month or so.