First off, it'd be called "Radder".
(I've got the most clever name ever for the third edition as well, to make for the perfect Trilogy, but I'm not telling. Don't even try to guess...)
Admittedly, it'd be a trifle formulaic. But hey...
Cru is again a senior in High School still, but has some new hip cool edgy name like Aden or something. He wants to get to the Xgames and compete in Park. He's got a little brother in a wheelchair, dying tragically from something. Only enjoyment he gets is playing Hoffman BMX video game...dreams of being able-bodied. Poor family, no dad around again. Aden fixes bike alongside his little bro who fixes or at least pretends to tinker with his wheelchair. He idolizes his big brother.
Aden is something of a Lone Wolf, as there are no other BMXers around. At all. Except one, his best friend and sidekick, who is a total zany geek cutup comic relief...totally lacking skills but not enthusiasm for BMX. Neither of them get any love from the at all from the geeks, brains, jocks, gearheads, skaters, etc. at school. Except the girls are all hot for Aden...cuz he's the sexy smart Lone Wolf that he is. He's always going on dates and being cornered and propositioned and whatnot, but the girls that are chasing him are all completely insane the way young sexy aggressive girls can be. Hilarity. (when it's not happening to you...imagine the drunk-driving chick in 40 yr. Old Virgin.)
Jealous boyfriends are chasing them in their car. Great potential for street riding stunt scenes.
He likes the visiting Nurse Aide who visits his little bro, but is too shy to say anything.
He's the only night shift security guy at a mall. He rides white tires so's not to leave marks and tapes up his pegs and pedals and barends and practices and trains for hardcore nine hours every night mon-fri inside the mall...improvising maneuvers on all sorts of architecually interesting structures. He invites the Nurse Aide for some window shopping some night and busts some moves and it's a really good scene.
For drama, this whole time, somebody is chasing Aden. Not important who or why at this point. The more the better. Not just jealous boyfriends. Like in the True Romance, you had the cops, the pimp, the mafiosa...or in Blues Brothers, where you had the cops and the nazis and and ex-fiance and Ray Charles and Aretha Franklin and the owners of Bob's Country Bunker and the Good Ole Boys and everybody else they ran into. At some point near the very climax, all the chasers converge.
So for whatever reason, all these people are chasing him (comedy/drama/action tri-fecta)...possibly for his bike (we'll iron out details later). Like I say not important exactly why at this point. Have a few beers with a funny friend and play AdLibs with a good funny motive and you're all set.
Against all odds, he makes it to the Xgames. He feels like a very small fish in a very large pond, rubbing elbows with the pros for the first time ever. Brilliantly funny cameos. Not only riders, but the judges will be cast as themselves and include Woody, Haro, McCoy, Hoffman, etc...
In fact there will cameos throughout.
Maurice Meyer will be the day security gaurd with a ****-on for his job.
I don't know Elvis, but I'd love to cast him in a role like David Letterman in Chris Elliot's Cabin Boy: "Hey, fancylad, Jennifer, wanna buy a monkey?".
Along with the trophy for the Park Event winner, is a prize of a vintage '82 Haro Freestyler, built up as a Haro replica or something really nice eye-candy-ish like that, as provided by event sponsor VBMX or whatever.
Doesn't get much respect. His bike looks pretty crappy in a custom kinda way. But of course when he rides he chokes and just doesn't hit anything cool like he did while practicing back home. Maybe he wins "best trick" during qualifyers...by accident or something...something totally amazing....that allows him to sneak into the finals! (didn't see that coming, did ya?)
Of course he still gets no respect from the other (playing charicaturistically snobby) Pros: "Yeah, If he could ever do that again, I'll give him my Mercedes..."
So anyhow, we're coming to the climax:
Everyone is chasing Aden after they catch up with him after qualifyers. They get his bike right before finals...practically as his name is being called to report for his final run. And he somehow gets injured. Not incapacitated, just banged up. Maybe he gets tazed or maced or drugged or whatever, too. Drama, baby. He cleverly loses these people in a tri-fecta way, but the point is...his bike is lost in the frenzy.
"Last chance for Aden Smith to report to the Xgames Park Arena for his final run..." the loudspeaker echoes. Cameras are showing a vacant riding area with Aden's name up on the Jumbotron and the announcers are trying to kill dead air time.
Aden looks out to see his little brother with his Nurse Aide across the bleachers. Mat Hoffman is there autographing the kid's game controller or something. Aden and his brothers eyes meet from a distance and in slo-motion, Aden can see the desperation in his dying eyes, and clearly see the kids mouth from the words "
What the **** are you doing?".
At the last moment Aden jumps on the Vintage BMX Freestyler trophy/prize and puts on the routine of a lifetime.
After that, Mat Hoffman freezes the little brother in Carbonite and kidnaps him and the Nurse Aide to his warehouse.
We'll leave the audience with a classic cliffhanger, to bring them back for "Raddest" (Oops, I guess the cat's out of the bag on that one...

)
It will involve battling rabid ninjas with uzi's at the warehouse, for the little bro and the chick. Tarentino will direct the last episode of the trilogy.