I am trying to decide what tires I should put on my sons BMX bike, he races regular dirt tracks, NBL stuff, and I just bought him a new bike, MCS with all the bells and whistles. I am thinking of putting on PRIMO slics, but has anyone heard anything bad about them? Are they dangerous, do people slip off the track more often, what are the kids using that are the fastest in the country? He is 9 Novice, and only weighs about 65 lbs. I want to figure out what the best parts I should put on his bike, and its hard to find this info. Is this something to just figure out on your own???? What about intense Micro Knobby tires? Does anyone have any profile cranks for sale, like a 165 or 170 mm arm?