I wish I still had the links, but from memory, my front rim is a 6 spoke, yours is a 5, but both are 2.5 " wide I think. That is not meant to mount a 120, which calls for a 3" wide rim. Look it up, I'm telling ya, It will deform the tire and if you ride like me (expect max performance) and set cruise control at 90 mph and ride with no hands, you don't want a 120 on the front. Sure it works , but it will not be round and does have impact on high speed handling and especially in corners. Your speedo will be off too. Since the tire is squeezed into a higher profile. I have a similar thread here as you do, for the same reason I suspect . Its the tire man, check its width compared to what its supposed to be from the factory, your find it taller and narrower.
On the other hand, your rim might be 3 " wide (ID), which case 120 is the right size

. Your owners manual should be able to tell you the front wheel width (2.5" is for 110/ 3" is 120)