I thought I'd share my aluminum 450r build with everyone. I just started today modifying a TRX450R swing arm to fit into my 05 CRF450 frame. I milled the swing arm down on both sides evenly to fit into the frame and also circle milled counter bores into the ends of the swing arm so the thrust washers would seat almost flush with the sides of the swing arm. With doing this I decided not to use the same seals for the opposite ends of the swing arm on the ends where the thrust washers press in. I also have my triple clamp blocks squared up and ready for machining. I'm hoping to have these done this week so I can start on the front hub and rotor assembly then move onto the rear shock mount. I'll be utilizing the CRF450 rear shock for this build also. My one issue I have so far is deciding on a motor. I'd like to use a CRF450X motor so this trike will have electric start. We will see if I can find a decent deal on one. Also does anyone know if an 03 or 04 CRF450r engine will fit properly in an 05 frame?