Traffic in Yosemite? NEVER SEEN IT EVER. ;-)
Seriously though, it all depends on when you show up. Mid to early April is when you are still rolling the dice on storms, but just enough of the snow is gone that you can ride in the valley. Waterfalls are flowing strong and it's beautiful. Honestly, the best motorcycle weather is around this time of year. A bit more chilly, crowds are dying down, all the kiddies are back in school. Find a way to camp out on a tues/wed/thurs and you're good.
Forgive my noobish-ness: "mo-betta hoon" and "RAA"? Translate please!