15 and a half you can get your permit. The permit allows you to ride, except that you can't ride at night, go on freeways, or take passengers. After 6 mos, you're 16 and you ca take the test for a full license. At least this was the case when I was that age. Even today I think you still only need to be 16.
Oh yeah,Yamaha YZF-R1 is the all around performance king. Hayabusa is a straight line sled, and an R1 weighs almost the same as an F4, but has alot more power. Current lap record for motorcycles at Willow Springs, is held my Chuck Graves on his R1. He was clocked going 160 in turn 8 (I used to do it at 120 on my Muzzy prepped '93 ZX7-R). He just hits the 180-185mph range before he hits the brakes going into one. His bike is totally built, but it is a great indicator of potential. The R1 is truly the standard by which all other sportbikes are compared to. Being an X motorcycle racer, I though I'd throw in my 2 copper pieces. Take it easy Bay Area friends! Arik : )