Hey there, that looks like a fun trail! What camera are you using? Are there different view angles on this thing? If so, set it to wide angle like 170 degrees. It looks like it was shot in 120, and that's just not wide enough to take in everything you want to show. The shakiness is also less perceptive the wider you go. If you can't, aim the cam upwards even more. It's better to see the trail to the horizon and not the bike than the other way around. My other advice would be to balance your color curves if you can. A lot of the video looks under saturated. Desaturation is great for raw footage, but you want to balance it out in post production.
It's a pentax wg-1. Not really designed for this sort of thing but it could do worse. When the new cameras arrives I'll do another run of the same trail for comparison, but it should be a lot better (adjustable angle, fps, newer sensor).
Didn't think about the colors or changing the view to show more of the trail, thanks for pointing it out.