Im filming snowboarding with my hvx but i am having some problems with the picture getting a bitt "blurry" and not smooth at all when im having the camera conneced to the tripod and the riders just "gets in and leaves" the pictre..
I'd play with frame rates and shutter speeds - the blurriness may be too slow of a shutter speed. Go for a faster frame rate and a faster shutter as well - what settings are you using that arent working? Whats the lighting like? Are you using ND filters at all? I'd bet if you shot at 720 60P with 1/120 or faster shutter you'd get some decent results. Thats just where i'd start out. Alot of that depends on your available light.
How wide is your composition? or rather how many snowboarders would it take to fill the frame stacked on top of each other? It sounds to me like maybe you've locked off a shot and despite the slomo the riders are only in frame for a few, which is still just a blink x2 or x2.5 as the case may be. At 24pn 60f the slowest possible shutter speed is 1/60th and I believe the default is 1/120th so you should get nice results if you do the work and track your subject. If you're committed to locking off the tripod then indeed use higher shutter speeds to the order of 1/250 or 1/500. Good Luck.